CVE-2026-108839

thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs

CVSS score

2.3

EPSS probability

—

Risk score

0.2

Published

1 d ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

Impact on My Inventory

Only the personal products you have added to your account are assessed; an organisation's inventory does not appear here.

Checking session…

Vulnerability description

CVE AI research

The stored explanation is shown at once; refreshing evaluates the sources again.

DayBreach AI Explanation

Verified against sources

thClaws up to 0.141.0 Symlink Following File Write Vulnerability

Sources read

Source agreement

0/2

Evidence confidence

%37

Short explanation

thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint. This allows authenticated uploads to write or truncate files outside the workspace by following symlinks.

Why does it matter?

This vulnerability enables attackers to interfere with files outside workspace boundaries using daemon privileges. There are conflicts between sources regarding the CVSS base score and severity.

What should be done?

Follow official vendor advisories
Restrict endpoint access

Note on uncertainty

3 alanda kaynak uyuşmazlığı var. DayBreach bu değerleri saklamadı; kaynak karşılaştırması aşağıda gösteriliyor.

Chain of evidence and sources2 verified claims

thClaws 0.141.0 ve önceki sürümler POST /v1/inputs uç noktasında sembolik bağlantı takip zafiyeti içerir.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Saldırganlar inputs/ ön eki altına yerleştirdikleri sembolik bağlantılar ile çalışma alanı dışına dosya yazabilir.

S0 · daybreach-canonical S1 · cvelist S2 · nvd

Show the technical text from the sources

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 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

CWE: CWE-59

Explanation produced with the local gemini-flash-lite-latest model. Numerical metrics and the KEV, patch and exploit statuses are not determined by AI.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-108839 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	thClaws	thClaws	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
4.2	CVSS V31	MEDIUM	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L	NVD
4.2	CVSS V3_1	MEDIUM	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L	CVE CNA
2.3	CVSS V40	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	NVD
2.3	CVSS V4_0	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	CVE CNA

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-108839 is associated with the following CWEs:

CWE-59: Common Weakness Enumeration Entry CWE-59

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-108839 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden

PermissionsGerekmiyor

User—

Official Sources and Advisories

https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escapevendor-advisory https://github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs#L335-L420vendor-advisory https://github.com/thClaws/thClawsvendor-advisory VulnCheck Advisory: thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputsvendor-advisory

CVSS Vector Radar Chart

2.3 / 10

Vulnerability Scoring Details

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

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone required

User InteractionP

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)P

Availability (Erişilebilirlik)Low

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

thClaws

Weakness Type (CWE & CAPEC)

CWE-59

Get this vulnerability through the API

Affected products, version ranges, exploitation status and patch information in a single request, with a free key.

Get a free key Documentation

curl -H "x-api-key: $DAYBREACH_API_KEY" \
  "https://api.enginteksut.com.tr/api/v1/intel/cves/CVE-2026-108839"