CVE-2025-61926: ossf allstar Insecure Default Variable Initialization

Vulnerability summary

CVE-2025-61926 is a medium (CVSS 4.6) Insecure Default Variable Initialization vulnerability in ossf allstar. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 32.2% of scored vulnerabilities.

Timeline

1. 09-10-2025
   PublishedVulnerability first disclosed.
2. 16-10-2025
   Last modifiedVulnerability information updated.

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.

• CWE-453Insecure Default Variable InitializationThe product, by default, initializes an internal variable with an insecure or less secure value than is possible.
• CWE-798Use of Hard-coded CredentialsThe product contains hard-coded credentials, such as a password or cryptographic key.