MediumCVE-2026-70427

Jenkins: Improper Link Resolution Before File Access ('Link Following') (CVE-2026-70427)

Published 27.08.2026Last modified 08.09.2026Sources: BSI

What is affected, what to do

A flaw was found in Jenkins. Attackers who can control agent processes can exploit this vulnerability by providing specially crafted .tar or .tar.gz archives to the Jenkins controller.

Update Jenkins to version 2.568.2, Jenkins to version 2.576.

Affected: Jenkins lt *..2.568.2
Jenkins lt 2.569..2.576
Fixed in: Jenkins 2.568.2
Jenkins 2.576

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

Metrics

4.3

Priority

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

Source: NVD, CVSS v3

4.3

CVSS v3

Severity Medium on the scale from 0 to 10.

Source: BSI

0.7 %

EPSS score

Low — model estimates < 1% exploitation likelihood.

Source: FIRST EPSS, percentile 52.0

Show all metrics

Severity: Medium
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: 47.88 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: 4.3 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: 4.3
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: 52.0; 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: 27.08.2026
CISA assessment (SSVC): Exploitation: none known · not automatable · Technical impact: partial; Source: CISA Vulnrichment, as of 5 August 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-59

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: Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
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 Jenkins. Attackers who can control agent processes can exploit this vulnerability by providing specially crafted .tar or .tar.gz archives to the Jenkins controller. This is due to unsafe handling of symbolic links with effectively empty names during archive extraction. Successful exploitation allows an attacker to write files to arbitrary locations on the file system, potentially leading to unauthorized data modification or system compromise.

Source: BSI WID Portal

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
Jenkins Project	Jenkins	`2.569 – < 2.576` `< 2.568.2`	`2.576` `2.568.2`
Jenkins Project	Jenkins AWS CodeBuild Plugin	`≤ 0.59`	—
Jenkins Project	Jenkins CodeSonar Plugin	`≤ 3.6.0`	—
Jenkins Project	Jenkins External Workspace Manager Plugin	`≤ 1.4.1`	—
Jenkins Project	Jenkins Google Chat Notification Plugin	`≤ 166.ve6b_de280f2e8`	—
Jenkins Project	Jenkins HCL AppScan Plugin	`≤ 1.8.3`	—
Jenkins Project	Jenkins Horreum Plugin	`≤ 0.16.162.v33b_4a_a_b_5f828`	—
Jenkins Project	Jenkins Ivy Report Plugin	`≤ 1.2`	—
Jenkins Project	Jenkins Multijob Plugin	`≤ 669.v9d96a_d9c71b_0`	—
Jenkins Project	Jenkins Parameterized Remote Trigger Plugin	`≤ 3.2.2`	—
Jenkins Project	Jenkins Qualys Container Scanning Connector Plugin	`≤ 1.8.0.5`	—
Jenkins Project	Jenkins Sauce OnDemand Plugin	`≤ 2.2.0`	—
Jenkins Project	Jenkins SCM-Manager Plugin	`≤ 1.11.1`	—
Jenkins Project	Jenkins Summary Display Plugin	`≤ 1.15`	—
Jenkins Project	Jenkins Violation Comments to GitLab Plugin	`≤ 2.62.0`	—
Jenkins Project	Jenkins Webhook Secret Credentials Provider Plugin	`≤ 16.v0cfa_f0215cf5`	—
Jenkins Project	Jenkins XML Job to Job DSL Plugin	`≤ 0.1.13`	—
Jenkins Project	Remoting	`< 3355.3357.v931d3c992987`	`3355.3357.v931d3c992987`
jenkins	jenkins	`< 2.568.2` `< 2.576`	`2.568.2` `2.576`
Jenkins	Jenkins AWS CodeBuild	`≤ 0.59`	—
Jenkins	Jenkins CodeSonar	`≤ 3.6.0`	—
Jenkins	Jenkins External Workspace Manager	`< 1.4.2`	`1.4.2`
Jenkins	Jenkins Google Chat Notification	`≤ 166.ve6b_de280f2e8`	—
Jenkins	Jenkins HCL AppScan	`< 1.8.4`	`1.8.4`
Jenkins	Jenkins Horreum	`≤ 0.16.162.v33b_4a_a_b_5f828`	—
Jenkins	Jenkins Ivy Report	`≤ 1.2`	—
Jenkins	Jenkins LTS	`< 2.568.2`	`2.568.2`
Jenkins	Jenkins Multijob	`< 677.v7ffc23d6a_4c2`	`677.v7ffc23d6a_4c2`
Jenkins	Jenkins Parameterized Remote Trigger	`≤ 3.2.2`	—
Jenkins	Jenkins Qualys Container Scanning Connector	`≤ 1.8.0.5`	—
Jenkins	Jenkins Sauce OnDemand	`≤ 2.2.0`	—
Jenkins	Jenkins SCM-Manager	`< 1.12.1`	`1.12.1`
Jenkins	Jenkins Violation Comments to GitLab	`≤ 2.62.0`	—
Jenkins	Jenkins Webhook Secret Credentials Provider	`< 32.v09c9b_522f0a_8`	`32.v09c9b_522f0a_8`
Jenkins	Jenkins weekly	`< 2.576`	`2.576`
Jenkins	Jenkins XML Job to Job DS	`≤ 0.1.13`	—

Distribution and container packages (1)

Downstream packages (e.g. Bitnami, Debian, Ubuntu, Red Hat). Versions refer to the distribution, not the vendor.

Distribution and container packages
		Affected versions	Fixed in
bitnami	jenkins	`2.569.0`	—

Vendors and products

Weakness classes (CWE)

CWE-59Improper Link Resolution Before File Access ('Link Following')
Base
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
Entry at MITRE CWE-59

References & sources

jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
NVD (NIST)vuln/detail/CVE-2026-70430web
jenkins.ioJenkins Security Advisory 2026-08-05web, Vendor advisory, Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
NVD (NIST)vuln/detail/CVE-2026-70426web
NVD (NIST)vuln/detail/CVE-2026-70429web
jenkins.ioJenkins Security Advisory 2026-08-05web, Vendor advisory, Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
NVD (NIST)vuln/detail/CVE-2026-70427web
jenkins.ioJenkins Security Advisory 2026-08-05web, Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory
jenkins.ioJenkins Security Advisory 2026-08-05Vendor advisory

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).

08.09.2026Initial analysis by NVDNVD

Newly listed as affected:

Jenkins (before 2.576; before 2.568.2)

New references:

https://www.jenkins.io/security/advisory/2026-08-05/#SECURITY-3930

Show 2 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Product configuration	added	—	OR cpe:2.3:a:jenkins:jenkins:::::-::: versions up to (excluding) 2.576 cpe:2.3:a:jenkins:jenkins:::::lts::: versions up to (excluding) 2.568.2
Reference type	added	—	Jenkins Project: https://www.jenkins.io/security/advisory/2026-08-05/#SECURITY-3930 Types: Vendor Advisory

Source identifier: nvd@nist.gov

05.08.2026Record modifiedCISA ADP

CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

CISA assessment (SSVC): exploitation: none known, automatable: no

Weakness type: CWE-59

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
CVSS	added	—	AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Weakness type (CWE)	added	—	CWE-59
SSVC assessment	added	—	{"id":"CVE-2026-70427","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"version":"2.0.3","timestamp":"2026-08-05T18:25:33.385273Z"}

Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

05.08.2026Receivedgooglegroups.com

Description added or changed

New references:

https://www.jenkins.io/security/advisory/2026-08-05/#SECURITY-3930

Show 3 original changes

Individual changes of this event as published by NVD
Type	Action	Before	After
Affected versions (publisher)	added	—	Jenkins
Description	added	—	Jenkins 2.575 and earlier, LTS 2.568.1 and earlier does not safely handle symbolic links with effectively empty names during the extraction of `.tar` and `.tar.gz` archives, allowing attackers able to control agent processes to provide crafted archives to the controller to write files to arbitrary locations on the file system, restricted only by file system access permissions of the user running Jenkins.
Reference	added	—	https://www.jenkins.io/security/advisory/2026-08-05/#SECURITY-3930

Source identifier: jenkinsci-cert@googlegroups.com

Linked CVEs

Linked CVEs

High	CVE-2026-70448	Jenkins Ivy Report Plugin: Improper Restriction of XML External Entity Reference	7.1	—
Medium	CVE-2026-70447	Jenkins AWS CodeBuild Plugin: Missing Authorization	4.3	—
Medium	CVE-2026-70446	Jenkins CodeSonar Plugin: Missing Authorization	4.3	—
Medium	CVE-2026-70445	Jenkins Sauce OnDemand Plugin: Missing Authorization	4.3	—
Medium	CVE-2026-70444	Jenkins Violation Comments to GitLab Plugin: Protection Mechanism Failure	4.3	—
Medium	CVE-2026-70443	Jenkins Horreum Plugin: Improper Privilege Management	4.3	—
Medium	CVE-2026-70442	Jenkins Google Chat Notification Plugin: Improper Authorization	4.3	—
Medium	CVE-2026-70441	Jenkins Summary Display Plugin: Cross-site Scripting	5.4	—
Medium	CVE-2026-70440	Jenkins Qualys Container Scanning Connector Plugin: Cross-site Scripting	5.4	—
Medium	CVE-2026-70439	Jenkins XML Job to Job DSL Plugin: Missing Authorization	6.5	—
Medium	CVE-2026-70438	Jenkins Parameterized Remote Trigger Plugin: Missing Authorization	4.3	—
Low	CVE-2026-70437	Jenkins Webhook Secret Credentials Provider Plugin: Observable Timing Discrepancy	3.7	—
Medium	CVE-2026-70436	Jenkins External Workspace Manager Plugin: Missing Authorization	4.3	—
Medium	CVE-2026-70435	Jenkins SCM-Manager Plugin: Missing Authorization	4.2	—
Medium	CVE-2026-70434	Jenkins SCM-Manager Plugin: Cross-Site Request Forgery (CSRF)	4.2	—
Medium	CVE-2026-70433	Jenkins HCL AppScan Plugin: Missing Authorization	4.3	—
High	CVE-2026-70432	Jenkins Multijob Plugin: Cross-Site Request Forgery (CSRF)	8.8	—
High	CVE-2026-70431	Jenkins Multijob Plugin: Code Injection	8.8	—
Low	CVE-2026-70430	Jenkins: Improper Access Control	2.7	—
High	CVE-2026-70429	Jenkins: Improper Handling of Case Sensitivity	8.1	—
Medium	CVE-2026-70428	Jenkins: Path Traversal	4.3	—
Medium	CVE-2026-70427	Jenkins: security vulnerability	4.3	—
Critical	CVE-2026-70426	Jenkins: Deserialization of Untrusted Data	9.0	—

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