CVE-2026-40256
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
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.
- Record
CVE-2026-40256- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
EUVDEUVD-2026-23019
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.
- Record
EUVD-2026-23019- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-ffgh-3jrf-8wvh
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
Impact
Weblate 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).
Patches
References
Thanks to m9nx4u for reporting this issue via HackerOne.
- Record
GHSA-ffgh-3jrf-8wvh- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-40256- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSV
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
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.
- Record
CVE-2026-40256- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVGHSA-ffgh-3jrf-8wvh
Weblate: Prefix-Based Repository Boundary Check Bypass via Symlink/Junction Path Prefix Collision
Impact
Weblate 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).
Patches
References
Thanks to m9nx4u for reporting this issue via HackerOne.
- Record
GHSA-ffgh-3jrf-8wvh- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Weakness
- CWE-22
- Updated
- 2026-11-02
OSVPYSEC-2026-2315
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.
- Record
PYSEC-2026-2315- CVSS 3.1
- 5.0 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
weblatePyPI |
before 5.17 | 5.17 |
weblatePyPI |
before 5.17, plus listed versions 1.92.02.12.102.10.1 Show 45 moreShow less2.112.122.132.13.12.142.14.12.152.162.172.17.12.182.192.19.12.22.202.32.42.52.62.72.82.93.03.0.13.13.1.13.103.10.13.10.23.10.33.113.11.13.11.23.11.33.23.2.13.2.23.33.43.53.5.13.63.6.13.73.7.1 |
5.17 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-40256 is a medium vulnerability (CVSS 5.0) in Weblate, published April 15, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 25th percentile. Fixed in weblate 5.17.
References
github.com/WeblateOrg/weblate/security/advisories/GHSA-ffgh-3jrf-8wvh
nvd.nist.gov/vuln/detail/CVE-2026-40256
Left out here: 113 versions. The JSON record has them.