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CVE-2026-108839

Status: DeferredLow (2.3)—
Severity2.3Low · CVSS 4.0
Exploitation probability0.25 %higher than 15% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

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.

CVSS

Base score
2.3
Version
4.0
Vector
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

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.25 %
Percentile among all scored CVEs
15
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

UI:R indica interacción del usuario (uploads autenticados posteriores). CWE-59 es symlink traversal que permite escritura fuera del workspace con privilegios daemon, causando manipulación de archivos y potencial escalada.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Application Isolation and SandboxingExploit ProtectionUpdate SoftwareThreat Intelligence ProgramExecution PreventionEncrypt Sensitive Information

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Thclaws — ThclawsAI

CWEs

References

Show 4 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-108839",
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          "modifiedAttackRequirements": "NOT_DEFINED",
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          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
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      "affectedData": [
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      "url": "https://github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs#L335-L420",
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      "lang": "en",
      "value": "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."
    }
  ],
  "lastModified": "2026-10-18T12:17:01.393",
  "sourceIdentifier": "disclosure@vulncheck.com"
}