What’s Vulnerable › Vulnerabilities

CVE-2026-108839: thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs

• Severity: medium (CVSS 4.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-11 · updated 2026-10-18
• Weakness: CWE-59

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.

Affected products

• thClaws: through 0.141.0

References

• https://github.com/thClaws/thClaws
• https://github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs#L335-L420
• https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escape
• https://www.vulncheck.com/advisories/thclaws-through-0.141.0-symlink-following-file-write-via-post-v1-inputs

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