CVE-2026-49248: CWE-61: UNIX Symbolic Link (Symlink) Following in theonedev onedev
OneDev is a Git server with CI/CD, kanban, and packages. In versions 15.0.6 and below, TarUtils.untar() creates symbolic links verbatim from TAR entry getLinkName() without validating whether the target is an absolute path. A subsequent file entry in the same archive traverses the symlink, writing to arbitrary server-side locations. This is exploitable by any authenticated user with CI Job write access — no admin interaction required. This is an incomplete fix bypass of CVE-2021-21251 (GHSA-2w6j-wc8c-9mq2): that patch blocked .. path segments but did not address absolute symlink targets. This issue has been fixed in version 15.0.7.
AI Analysis
Technical Summary
The vulnerability in OneDev (CVE-2026-49248) involves improper handling of symbolic links during TAR archive extraction in versions 15.0.6 and earlier. The TarUtils.untar() method creates symlinks exactly as specified in the TAR entry without checking if the link target is an absolute path. This flaw enables an authenticated user with CI Job write permissions to exploit the symlink to write files to arbitrary locations on the server. This vulnerability is a bypass of a prior fix for CVE-2021-21251, which only blocked relative path traversal but did not prevent absolute symlink targets. The issue is fixed in OneDev version 15.0.7.
Potential Impact
An attacker with authenticated CI Job write access can leverage this vulnerability to write files to arbitrary locations on the server by exploiting absolute symbolic links in TAR archives. This can lead to unauthorized file modification or potential code execution depending on the server configuration. No administrative privileges or user interaction beyond authentication and write access are required.
Mitigation Recommendations
This vulnerability has been fixed in OneDev version 15.0.7. Users should upgrade to version 15.0.7 or later to remediate this issue. Since the vendor advisory does not provide additional remediation details or temporary fixes, upgrading is the recommended action.
CVE-2026-49248: CWE-61: UNIX Symbolic Link (Symlink) Following in theonedev onedev
Description
OneDev is a Git server with CI/CD, kanban, and packages. In versions 15.0.6 and below, TarUtils.untar() creates symbolic links verbatim from TAR entry getLinkName() without validating whether the target is an absolute path. A subsequent file entry in the same archive traverses the symlink, writing to arbitrary server-side locations. This is exploitable by any authenticated user with CI Job write access — no admin interaction required. This is an incomplete fix bypass of CVE-2021-21251 (GHSA-2w6j-wc8c-9mq2): that patch blocked .. path segments but did not address absolute symlink targets. This issue has been fixed in version 15.0.7.
CVSS v4.0
Score 8.3high
Affected software
Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in OneDev (CVE-2026-49248) involves improper handling of symbolic links during TAR archive extraction in versions 15.0.6 and earlier. The TarUtils.untar() method creates symlinks exactly as specified in the TAR entry without checking if the link target is an absolute path. This flaw enables an authenticated user with CI Job write permissions to exploit the symlink to write files to arbitrary locations on the server. This vulnerability is a bypass of a prior fix for CVE-2021-21251, which only blocked relative path traversal but did not prevent absolute symlink targets. The issue is fixed in OneDev version 15.0.7.
Potential Impact
An attacker with authenticated CI Job write access can leverage this vulnerability to write files to arbitrary locations on the server by exploiting absolute symbolic links in TAR archives. This can lead to unauthorized file modification or potential code execution depending on the server configuration. No administrative privileges or user interaction beyond authentication and write access are required.
Mitigation Recommendations
This vulnerability has been fixed in OneDev version 15.0.7. Users should upgrade to version 15.0.7 or later to remediate this issue. Since the vendor advisory does not provide additional remediation details or temporary fixes, upgrading is the recommended action.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-28T14:33:01.178Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a3456d1f198dc38c18207e2
Added to database: 06/18/2026, 20:36:33 UTC
Last enriched: 06/25/2026, 21:17:19 UTC
Last updated: 08/02/2026, 19:17:59 UTC
Views: 75
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.