Jenkins Pipeline: Groovy Libraries Plugin: Improper Link Resolution Before File Access
CVE-2026-48921 is a high-severity improper link resolution before file access vulnerability in Jenkins Pipeline: Groovy Libraries Plugin from Jenkins, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected Jenkins Pipeline: Groovy Libraries Plugin versions: 797.v90ea_a_9b_e45a_0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.29% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Pipeline to 798.v5cc688825312 or a later version.
- Read the advisory on jenkins.io for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Jenkins Project | Jenkins Pipeline: Groovy Libraries Plugin | 797.v90ea_a_9b_e45a_0 and earlier | Not stated |
| Jenkins | Pipeline | before 798.v5cc688825312 | 798.v5cc688825312 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
Jenkins Pipeline: Groovy Libraries Plugin 797.v90ea_a_9b_e45a_0 and earlier does not prohibit symbolic links in shared libraries, allowing attackers able to control the content of a library used by a Pipeline job to read arbitrary files on the Jenkins controller filesystem.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Link Resolution Before File Access
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.
How developers prevent this class of flaw
- Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.
More Improper Link Resolution Before File Access vulnerabilities (CWE-59)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Recent Improper Link Resolution Before File Access vulnerabilities
- 7.9 High severity
- 9.9 Critical severity
- 7.5 High severity
- 9.1 Critical severity
- 7.8 High severity
- 8.1 High severity
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