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Fencer Intel
medium 4.6

CVE-2025-61926 json

Allstar Reviewbot has Authentication Bypass via Hard-coded Webhook Secret

published last yr. modified last mo. also GHSA-33f4-mjch-7fpr , GO-2025-4018 , EUVD-2025-33544

cvss
4.6
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

Allstar is a GitHub App to set and enforce security policies. In versions prior to 4.5, a vulnerability in Allstar’s Reviewbot component caused inbound webhook requests to be validated against a hard-coded, shared secret. The value used for the secret token was compiled into the Allstar binary and could not be configured at runtime. In practice, this meant that every deployment using Reviewbot would validate requests with the same secret unless the operator modified source code and rebuilt the component - an expectation that is not documented and is easy to miss. All Allstar releases prior to v4.5 that include the Reviewbot code path are affected. Deployments on v4.5 and later are not affected. Those who have not enabled or exposed the Reviewbot endpoint are not exposed to this issue.

Patch / fix

  • go github.com/ossf/allstar 0.0.0-20250721181116-e004ecb540d6
  • govulncheck-vulndb SLE Module for Package Hub 15 SP6, openSUSE Leap 15.6 0.0.20251023T162509-150000.1.110.1

suse advisories SUSE-SU-2025:3799-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • govulncheck-vulndb openSUSE Tumbleweed 0.0.20251023T162509-1.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2025:15666-1

Is CVE-2025-61926 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/ossf/allstar/security/advisories/GHSA-33f4-mjch-7fpr referenced PoC, tagged "exploit" by a source, unverified
  • github.com https://github.com/ossf/allstar/blob/294ae985cc2facd0918e8d820e4196021aa0b914/pkg/reviewbot/reviewbot.go#L59 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 4.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
CNA 4.0 4.6 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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

Affected packages

ecosystem package affected fixed in
go github.com/ossf/allstar
<0.0.0-20250721181116-e004ecb540d6
0.0.0-20250721181116-e004ecb540d6

Affected products

  • ossf allstar

Classification

Weakness
  • CWE-453 Insecure Default Variable Initialization
  • CWE-798 Use of Hard-coded Credentials

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.