CVE-2025-61926: ossf allstar · Insecure Default Variable Initialization
Affects ossf allstarSource CVE Database V5
Not known to be exploited · CVSS 4.6 Medium · fixed in 4.5 : update ossf allstar when convenient.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.5
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:UExploitation evidence
Disclosed: evidence found.
CVE published 9 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
AI-suggested
European organizations should first inventory their use of ossf allstar and determine if the Reviewbot component is enabled and exposed. If so, immediate upgrade to version 4.5 or later is essential to eliminate the hard-coded secret vulnerability. If upgrading is not immediately feasible, organizations should consider disabling the Reviewbot endpoint to mitigate exposure. Additionally, operators should audit webhook configurations and monitor for unusual or unauthorized webhook activity that could indicate exploitation attempts. Implementing network-level restrictions to limit inbound webhook requests to trusted IP ranges can reduce risk. Organizations should also review their internal policies and documentation to ensure that any custom builds of allstar do not contain hard-coded secrets and that secrets are managed securely using environment variables or secret management tools. Finally, integrating webhook request validation with dynamic, per-deployment secrets and rotating these secrets regularly will prevent similar issues in the future.
Description
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.
References
- github.com/ossf/allstar/security/advisories/GHSA-33f4-mjch-7fpr (opens in a new tab)
- github.com/ossf/allstar/pull/713 (opens in a new tab)
- github.com/ossf/allstar/commit/e004ecb540d63ca6f5b1689b41af6c0040a82c73 (opens in a new tab)
- github.com/ossf/allstar/blob/294ae985cc2facd0918e8d820e4196021aa0b914/pkg/reviewbot/reviewbot.go (opens in a new tab)