thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs
Summary
| CVE | CVE-2026-108839 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-11 14:17:04 UTC |
| Updated | 2026-10-11 14:17:04 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 2.3 LOW from [email protected]
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
Problem Types: CWE-59 | CWE-59 Improper Link Resolution Before File Access ('Link Following')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 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/C... |
| 4.0 | CNA | CVSS | 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 |
| 3.1 | [email protected] | Primary | 4.2 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L |
| 3.1 | CNA | CVSS | 4.2 | MEDIUM | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
PassiveConfidentiality
NoneIntegrity
LowAvailability
LowSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS: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 v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
LowCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escape | [email protected] | hackmd.io | |
| www.vulncheck.com/advisories/thclaws-through-0.141.0-symlink-following-file-wri... | [email protected] | www.vulncheck.com | |
| github.com/thClaws/thClaws | [email protected] | github.com | |
| github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifact... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: hieuPenguinnn (en)
There are currently no legacy QID mappings associated with this CVE.