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

> Attackers can bypass webhook authentication in Allstar Reviewbot using a hard-coded secret, allowing unauthorized policy enforcement actions.

- **Severity:** Medium 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Oct 2025
- **Updated:** 16 Oct 2025
- **Also known as:** GHSA-33f4-mjch-7fpr, GO-2025-4018

## What is CVE-2025-61926?

CVE-2025-61926 is a medium-severity vulnerability in ossf allstar, published on 9 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-798 (Use of Hard-coded Credentials), CWE-453 (Insecure Default Variable Initialization)

## Which versions are affected by CVE-2025-61926?

3 open source packages ship an affected version, including github.com/ossf/allstar.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/ossf/allstar` | Go | All versions | 0.0.0-20250721181116-e004ecb540d6 |
| `github.com/ossf/allstar` | Go | All versions | 0.0.0-20250721181116-e004ecb540d6 |
| `github.com/ossf/allstar` | Go | All versions | 0.0.0-20250721181116-e004ecb540d6 |

## How do I fix CVE-2025-61926?

Upgrade github.com/ossf/allstar to 0.0.0-20250721181116-e004ecb540d6 or later.

## Is CVE-2025-61926 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-61926 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-61926 and fix it if it is affected.

What it is: CVE-2025-61926 is a medium-severity vulnerability in ossf allstar, published on 9 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-61926 exists.

Affected packages and fixed versions:
- github.com/ossf/allstar (Go): affected all versions; fixed in 0.0.0-20250721181116-e004ecb540d6
- github.com/ossf/allstar (Go): affected all versions; fixed in 0.0.0-20250721181116-e004ecb540d6
- github.com/ossf/allstar (Go): affected all versions; fixed in 0.0.0-20250721181116-e004ecb540d6

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-61926/ (Markdown: https://insights.sbomify.com/CVE-2025-61926/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-61926
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-61926
- OSV: https://osv.dev/vulnerability/CVE-2025-61926

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-61926/
Summaries are generated and may contain mistakes; the official description above is the record.