CVE-2026-40256 json
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
published 6mo ago modified 14d ago also EUVD-2026-23019 , GHSA-ffgh-3jrf-8wvh , PYSEC-2026-2315
- cvss
- 5.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 25%
- public exploits
- 0
- none known
Summary
Weblate is a web based localization tool. In versions prior to 5.17, repository-boundary validation relies on string prefix checks on resolved absolute paths. In multiple code paths, the check uses startswith against the repository root path. This is not path-segment aware and can be bypassed when the external path shares the same string prefix as the repository path (for example, repo and repo_outside). This issue has been fixed in version 5.17.
Patch / fix
- pypi weblate 5.17
- weblate weblate 5.17
Is CVE-2026-40256 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6mo ago
Exploit prediction
0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
| GitHub | 3.1 | 5.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
| OSV | 3.1 | 5.0 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| pypi | weblate | <5.17 |
5.17 |
Affected products
- WeblateOrg weblate
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/WeblateOrg/weblate/commit/e30dbcb33ae78e754ecef192d54f996b89cb4e15
web, patch
-
github.com
/WeblateOrg/weblate/security/advisories/GHSA-ffgh-3jrf-8wvh
web, patch, vendor-advisory
-
github.com
/WeblateOrg/weblate/pull/18847
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-40256
advisory
-
github.com
/WeblateOrg/weblate
package
Sources
- CVE List CVE-2026-40256
- GitHub Advisory GHSA-ffgh-3jrf-8wvh
- NVD CVE-2026-40256
- OSV PYSEC-2026-2315
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.