CriticalCVE-2026-39892

cryptography has a buffer overflow if non-contiguous buffers were passed to APIs (CVE-2026-39892)

Published 08.04.2026Last modified 10.09.2026Sources: Red Hat, BSI, OSV, CVE.org

What is affected, what to do

Update cryptography to version 46.0.7, App Connect Enterprise Certified Container to version 13.0.0, Concert to version 3.0.0.

Affected: Pyca Cryptography gte 45.0.0, < 46.0.7..*

Not sure whether and how you are affected? Ask a question about this vulnerability

Metrics

9.8

Priority

XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

Source: NVD, CVSS v3

9.8

CVSS v3

Severity Critical on the scale from 0 to 10.

Source: Red Hat, BSI, OSV, CVE.org

0.7 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 51.1

Show all metrics

Severity: Critical
Priority (0–325) The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first? Read in glossary: 85.91 Methodology
Exploit maturity An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack. Read in glossary: no public PoC known
XIEM Effective CVSS XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command. Read in glossary: 9.8 Methodology
CVSS v3 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 9.8
CVSS v4 CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions. Read in glossary: 6.9
EPSS score The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“. Read in glossary: 0.7 %; Low — model estimates < 1% exploitation likelihood.
EPSS percentile The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking. Read in glossary: 51.1; High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching. Read in glossary: —
Published: 08.04.2026
CISA assessment (SSVC): Exploitation: none known · automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 9 April 2026
CWE CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect. Read in glossary: CWE-119

Detection rules

No NEOSEC detection rule is available for this vulnerability yet.

Classification under NIS2 and CRA

Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

NIS2 NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management. Read in glossary: High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
CRA The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates. Read in glossary: From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
ISO/IEC 27001 ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security. Read in glossary: Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

Description

A flaw was found in the cryptography library. This vulnerability occurs when a non-contiguous buffer is passed to certain application programming interfaces (APIs) that accept Python buffers, such as Hash.update(). A remote attacker could exploit this to cause a buffer overflow, potentially leading to a denial of service.

Source: redhat_csaf, BSI WID Portal, BSI CSAF, OSV (Open Source Vulnerabilities), cvelistv5, NVD (NIST), CVE.org (MITRE)

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

Affected products
		Affected versions	Fixed in
pyca	cryptography	`≥ 45.0.0, < 46.0.7`	—
cryptography.io	cryptography	`45.0.0 – < 46.0.7`	`46.0.7`
IBM	App Connect Enterprise	`Certified Container <12.0 LTS`	—
IBM	App Connect Enterprise Certified Container	`< 13.0.0`	`13.0.0`
IBM	Concert	`< 3.0.0`	`3.0.0`
Oracle	Communications	`7.5.0` `15.0.1.0.0` `26.1.202` `7.7.0` `25.1.100` `47.0.0.2.0` `7.0.0` `6` `6.1` `7.8.0` `24.2.4-25.2.000` `7.5.1` `25.2.100` `8.0-8.1` `8.0.1` `7.6.0` `14` `15.1.0.0.0` `25.1.200` `6.1.1-7.0.0` `25.2.200` `15.2.0.0.0` `11` `26.1.200` `25.2.202` `25.2.201` `15.0.0.0.0` `8.0-8.3`	— — — — — — — — — — — — — — — — — — — — — — — — — — — —
pypi	cryptography	`45.0.7` `46.0.4` `46.0.3` `46.0.1` `45.0.2` `46.0.5` `46.0.0` `45.0.5` `45.0.0` `46.0.2` `45.0.3` `45.0.1` `46.0.6` `45.0.4` `45.0.6`	— — — — — — — — — — — — — — —

Vendors and products

Weakness classes (CWE)

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
Class
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
Entry at MITRE CWE-119

References & sources

openwall.comlists/oss-security/2026/04/08/12advisory
github.compyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmqadvisory, x_refsource_CONFIRM
access.redhat.comsecurity/cve/CVE-2026-39892Vulnerability database, x_refsource_REDHAT
bugzilla.redhat.comRHBZ#2456735Issue tracking, x_refsource_REDHAT
security.access.redhat.comdata/csaf/v2/vex/2026/cve-2026-39892.jsonx_sadp-csaf-vex
access.redhat.comerrata/RHSA-2026:24761Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:24762Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:30089Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:30088Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:24866Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:20338Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43855Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43854Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43851Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43670Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43853Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:43651Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:46956Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:7295Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:42644Vendor advisory, x_refsource_REDHAT

Changes to this CVE

Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

10.09.2026Record modifiedGitHub

New references:

https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq
Reference	removed	https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq	—
Reference type	removed	https://github.com/pyca/cryptography/security/advisories/GHSA-p423-j2cm-9vmq Types: Vendor Advisory	—

Source identifier: security-advisories@github.com

10.09.2026Record modifiedCVE Program

New references:

http://www.openwall.com/lists/oss-security/2026/04/08/12

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	http://www.openwall.com/lists/oss-security/2026/04/08/12
Reference	removed	http://www.openwall.com/lists/oss-security/2026/04/08/12	—
Reference type	removed	http://www.openwall.com/lists/oss-security/2026/04/08/12 Types: Mailing List, Release Notes, Third Party Advisory	—

Source identifier: af854a3a-2127-422b-91ae-364da2661108

10.09.2026Record modifiedRed Hat ADP

New references:

and 8 more references

Show 57 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/39xxx/CVE-2026-39892.json">CVE-2026-39892</a>
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:19375
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:20338
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:21017
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:22465
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:22629
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:22840
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:23361
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24483
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24761
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24762
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24853
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24866
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:24977
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:30088
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:30089
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:37275
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:42644
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43651
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43670
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43851
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43853
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43854
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43855
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:46956
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:7295
Reference	added	—	https://access.redhat.com/security/cve/CVE-2026-39892
Reference	added	—	https://bugzilla.redhat.com/show_bug.cgi?id=2456735
Reference	added	—	https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39892.json
Reference	removed	https://access.redhat.com/errata/RHSA-2026:19375	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:20338	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:21017	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:22465	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:22629	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:22840	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:23361	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24483	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24761	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24762	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24853	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24866	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:24977	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:30088	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:30089	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:37275	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:42644	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43651	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43670	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43851	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43853	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43854	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:43855	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:46956	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:7295	—
Reference	removed	https://access.redhat.com/security/cve/CVE-2026-39892	—
Reference	removed	https://bugzilla.redhat.com/show_bug.cgi?id=2456735	—
Reference	removed	https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-39892.json	—

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

30.07.2026Record modifiedRed Hat ADP

1 individual change: Affected versions (publisher)

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	changed	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+93)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+93)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

28.07.2026Record modifiedRed Hat ADP

New references:

https://access.redhat.com/errata/RHSA-2026:46956

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:46956
Affected versions (publisher)	changed	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+92)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+93)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

Show 3 older changes

23.07.2026Record modifiedRed Hat ADP

New references:

and 2 more references

Show 7 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43651
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43670
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43851
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43853
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43854
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:43855
Affected versions (publisher)	changed	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+89)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+92)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

21.07.2026Record modifiedRed Hat ADP

New references:

https://access.redhat.com/errata/RHSA-2026:42644

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:42644
Affected versions (publisher)	changed	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+88)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+89)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

20.07.2026Record modifiedRed Hat ADP

1 individual change: Affected versions (publisher)

Show the original change

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	changed	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+88)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9 (+88)

Source identifier: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

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<a href="https://intel.neosec.eu/en/cve/CVE-2026-39892"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-39892.svg?lang=en" alt="CVE-2026-39892 – NEOSEC Intel" height="20"></a>