How severe is CVE-2026-35628?

No CVSS score has been assigned to CVE-2026-35628 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-35628?

CVE-2026-35628 affects the following packages: openclaw (npm). Ecosystems affected: npm.

How do I fix CVE-2026-35628?

No patched version of openclaw has shipped for CVE-2026-35628 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2026-35628 in my npm dependencies?

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

How do I mitigate CVE-2026-35628 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-35628?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-35628 can be triaged on real exposure rather than presence alone.

Is CVE-2026-35628 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-35628 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-2026-35628?

CVE-2026-35628 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 21th 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-2026-35628?

CVE-2026-35628 is classified as CWE-307 (CWE-307). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-35628 published, and has it been updated?

CVE-2026-35628 was published on April 9, 2026 and was last updated on August 12, 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-2026-35628 — openclaw

Fix: openclaw/openclaw@c2c136a

CVE-2026-35628 is a CWE-307 vulnerability in openclaw. No vendor fix is recorded yet; mitigation options are listed below.

OpenClaw < 2026.3.25 - Brute-Force Attack via Missing Telegram Webhook Rate Limiting

Also known asGHSA-vcx4-4qxg-mfp4

Published

Apr 9, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

See advisory

Exploits

None indexed

Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-35628.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs21th percentile — riskier than 21% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

133other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

openclawnpm

2.5Mdownloads / week

Description

Summary

Telegram Webhook Missing Guess Rate Limiting Enables Brute-Force Guessing of Weak Webhook Secret

Affected Packages / Versions

Package: openclaw
Affected versions: <= 2026.3.24
First patched version: 2026.3.25
Latest published npm version at verification time: 2026.3.24

Details

Telegram webhook auth previously rejected bad secrets but did not throttle repeated guesses, allowing brute-force attempts against weak webhook secrets. Commit c2c136ae9517ddd0789d742a0fdf4c10e8c729a7 adds repeated-guess throttling before auth failure responses.

Verified vulnerable on tag v2026.3.24 and fixed on main by commit c2c136ae9517ddd0789d742a0fdf4c10e8c729a7.

Fix Commit(s)

c2c136ae9517ddd0789d742a0fdf4c10e8c729a7

Release Process Note

2026.3.25 is the next planned OpenClaw release version in package.json. This advisory is being published ahead of that npm release so the draft is no longer blocked; once 2026.3.25 is published, the structured patched-version metadata will match the released artifact.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
📦npm	`openclaw`	all versions	No fix

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for openclaw, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of openclaw has shipped for CVE-2026-35628 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-35628 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2026-35628. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary Telegram Webhook Missing Guess Rate Limiting Enables Brute-Force Guessing of Weak Webhook Secret ## Affected Packages / Versions - Package: `openclaw` - Affected versions: `<= 2026.3.24` - First patched version: `2026.3.25` - Latest published npm version at verification time: `2026.3.24` ## Details Telegram webhook auth previously rejected bad secrets but did not throttle repeated guesses, allowing brute-force attempts against weak webhook secrets. Commit `c2c136ae9517ddd0789d742a0fdf4c10e8c729a7` adds repeated-guess throttling before auth failure responses. Verified vulnerabl

O3 Security · Impact-Aware SCA

Is CVE-2026-35628 in your dependencies?

O3 Security finds CVE-2026-35628 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

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