HighCVE-2026-26007

cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves (CVE-2026-26007)

Published 10.02.2026Last modified 10.09.2026Sources: Red Hat, BSI, CVE.org, OSV

What is affected, what to do

A validation flaw has been discovered in the python cryptography package. This missing validation allows an attacker to provide a public key point P from a small-order subgroup.

Update Pyca Cryptography to version 46.0.5.

Affected: Pyca Cryptography lt *..46.0.5
Fixed in: Pyca Cryptography 46.0.5

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

Metrics

8.2

Priority

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

Source: NVD, CVSS v4

6.5

CVSS v3

Severity Medium on the scale from 0 to 10.

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

0.4 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 33.1

Show all metrics

Severity: High
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: 63.92 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: 8.2 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: 6.5
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: 8.2
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: 0.4 %; 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: 33.1; Elevated — this CVE ranks above at least 10% of all CVEs scored today.
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: 10.02.2026
CISA assessment (SSVC): Exploitation: none known · not automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 11 February 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-345

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 validation flaw has been discovered in the python cryptography package. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the victim computes the shared secret as S = [victim_private_key]P via ECDH, this leaks information about victim_private_key mod (small_subgroup_order). For curves with cofactor > 1, this reveals the least significant bits of the private key. When these weak public keys are used in ECDSA , it's easy to forge signatures on the small subgroup. Only SECT curves are impacted by this.

Source: redhat_csaf, BSI WID Portal, BSI CSAF, cvelistv5, OSV (Open Source Vulnerabilities), 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	`< 46.0.5`	`46.0.5`
cryptography.io	cryptography	`< 46.0.5`	`46.0.5`
IBM	Concert	`< 3.0.0`	`3.0.0`
Oracle	Siebel CRM	`17.0-26.5`	—
Splunk	SOAR	`< 8.6.0`	`8.6.0`
pypi	cryptography	`38.0.4` `2.1.2` `0.6` `2.3` `41.0.2` `42.0.2` `45.0.7` `36.0.1` `42.0.7` `42.0.6` `2.0.2` `1.2` `2.4` `2.0.3` `42.0.3` `41.0.7` `0.2.2` `3.1` `2.7` `0.7` `38.0.0` `46.0.4` `46.0.3` `3.2` `2.2.2` `2.4.1` `2.1.1` `39.0.0` `46.0.1` `42.0.4` `42.0.1` `1.0` `2.5` `0.5.2` `0.8.2` `37.0.4` `45.0.2` `1.2.2` `2.8` `0.7.1` `0.2.1` `2.1.3` `0.8`	— — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — — —

Vendors and products

Weakness classes (CWE)

CWE-345Insufficient Verification of Data Authenticity
Class
The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
Entry at MITRE CWE-345

References & sources

access.redhat.comsecurity/cve/CVE-2026-26007web, Vulnerability database, x_refsource_REDHAT
security.access.redhat.comdata/csaf/v2/vex/2026/cve-2026-26007.jsonweb, x_sadp-csaf-vex
openwall.comlists/oss-security/2026/02/10/4advisory
access.redhat.comerrata/RHSA-2026:10184advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:12176advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:13512advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:13545advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:13553advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:13672advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:19355advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:21431advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:21517advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:22330advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:22993advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:2694advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:5168advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:5665advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:6308advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:6309advisory, Vendor advisory, x_refsource_REDHAT
access.redhat.comerrata/RHSA-2026:6497advisory, Vendor 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:

Show 6 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Reference	added	—	https://github.com/pyca/cryptography/commit/0eebb9dbb6343d9bc1d91e5a2482ed4e054a6d8c
Reference	added	—	https://github.com/pyca/cryptography/security/advisories/GHSA-r6ph-v2qm-q3c2
Reference	removed	https://github.com/pyca/cryptography/commit/0eebb9dbb6343d9bc1d91e5a2482ed4e054a6d8c	—
Reference	removed	https://github.com/pyca/cryptography/security/advisories/GHSA-r6ph-v2qm-q3c2	—
Reference type	removed	https://github.com/pyca/cryptography/commit/0eebb9dbb6343d9bc1d91e5a2482ed4e054a6d8c Types: Patch	—
Reference type	removed	https://github.com/pyca/cryptography/security/advisories/GHSA-r6ph-v2qm-q3c2 Types: Vendor Advisory	—

Source identifier: security-advisories@github.com

10.09.2026Record modifiedCVE Program

New references:

http://www.openwall.com/lists/oss-security/2026/02/10/4

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/2026/02/10/4
Reference	removed	http://www.openwall.com/lists/oss-security/2026/02/10/4	—
Reference type	removed	http://www.openwall.com/lists/oss-security/2026/02/10/4 Types: Mailing List, Third Party Advisory	—

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

10.09.2026Record modifiedRed Hat ADP

New references:

and 8 more references

Show 47 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/2026/26xxx/CVE-2026-26007.json">CVE-2026-26007</a>
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:10184
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:12176
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:13512
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:13545
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:13553
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:13672
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:19355
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:21431
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:21517
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:22330
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:22993
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:2694
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:5168
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:5665
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:6308
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:6309
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:6497
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:6567
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:6568
Reference	added	—	https://access.redhat.com/errata/RHSA-2026:7295
Reference	added	—	https://access.redhat.com/security/cve/CVE-2026-26007
Reference	added	—	https://bugzilla.redhat.com/show_bug.cgi?id=2438762
Reference	added	—	https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26007.json
Reference	removed	https://access.redhat.com/errata/RHSA-2026:10184	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:12176	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:13512	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:13545	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:13553	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:13672	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:19355	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:21431	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:21517	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:22330	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:22993	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:2694	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:5168	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:5665	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:6308	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:6309	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:6497	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:6567	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:6568	—
Reference	removed	https://access.redhat.com/errata/RHSA-2026:7295	—
Reference	removed	https://access.redhat.com/security/cve/CVE-2026-26007	—
Reference	removed	https://bugzilla.redhat.com/show_bug.cgi?id=2438762	—
Reference	removed	https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-26007.json	—

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 9, Red Hat Enterprise Linux 8 (+70)	Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9, Red Hat Enterprise Linux 8 (+70)

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

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<a href="https://intel.neosec.eu/en/cve/CVE-2026-26007"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-26007.svg?lang=en" alt="CVE-2026-26007 – NEOSEC Intel" height="20"></a>