CVE-2026-31852: jellyfin code-quality.yml · Improper Privilege Management
Affects jellyfin code-quality.ymlSource CVE Database V5
Not known to be exploited · CVSS 10.0 Critical.
Data as of 30 Oct 2026, 11:52 UTC
Contested
Critical score, yet low EPSS after six months- EPSS
- 0.4% chance of exploitation in 30 days – higher than 40% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jellyfincode-quality.yml | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2026-31852, repository maintainers must immediately review and restrict the permissions granted to GitHub Actions workflows, especially those triggered by pull requests from forked repositories. Specifically, the code-quality.yml workflow should be updated to use the least privilege principle by limiting write permissions and avoiding the use of secrets or tokens in workflows triggered by untrusted contributors. Implementing GitHub's recommended best practices for workflow security, such as enabling 'pull_request_target' workflows only when necessary and avoiding exposing sensitive secrets to forked pull requests, is critical. Additionally, maintainers should consider using environment protection rules, required reviewers, and branch protection policies to reduce the risk of unauthorized workflow execution. Regular audits of CI/CD configurations and secrets management policies are advised to detect and remediate similar misconfigurations. Organizations consuming Jellyfin iOS builds should verify the integrity of builds and monitor for suspicious activity related to supply chain attacks. While no user action is required, developers and maintainers must prioritize updating workflow permissions to prevent exploitation.
Description
Jellyfin is an open-source media system. The code-quality.yml GitHub Actions workflow in jellyfin/jellyfin-ios is vulnerable to arbitrary code execution via pull requests from forked repositories. Due to the workflow's elevated permissions (nearly all write permissions), this vulnerability enables full repository takeover of jellyfin/jellyfin-ios, exfiltration of highly privileged secrets, Apple App Store supply chain attack, GitHub Container Registry (ghcr.io) package poisoning, and full jellyfin organization compromise via cross-repository token usage. Note: This is not a code vulnerability, but a vulnerability in the GitHub Actions workflows. No new version is required for this GHSA and end users do not need to take any actions.