CVE-2026-108839
thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
- Record
CVE-2026-108839- CVSS 4.0
- 2.3 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N - CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L - Weakness
- CWE-59
- Updated
- 2026-11-02
EUVDEUVD-2026-97000
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
- Record
EUVD-2026-97000- CVSS 4.0
- 2.3 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-8c39-3r7m-gwc4
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the...
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
- Record
GHSA-8c39-3r7m-gwc4- CVSS 4.0
- 2.3 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L - Weakness
- CWE-59
- Updated
- 2026-11-02
NVD
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
- Record
CVE-2026-108839- CVSS 4.0
- 2.3 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L - Weakness
- CWE-59
- Updated
- 2026-11-02
OSV
thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs
thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.
- Record
CVE-2026-108839- CVSS 4.0
- 2.3 Low
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N - Weakness
- CWE-59
- Updated
- 2026-11-02
Affected products
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-2026-108839 is a low vulnerability (CVSS 2.3) in Thclaws, published October 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.25%, the 16th percentile. No source names a fixed version.
References
hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escape
github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs
vulncheck.com/advisories/thclaws-through-0.141.0-symlink-following-file-write-via-post-v1-inputs
nvd.nist.gov/vuln/detail/CVE-2026-108839