Critical severity · published May 12, 2026
CVE-2026-42300
DevGuard: Unauthenticated identity assertion via `X-Admin-Token` header
9.3
CVSS
0.3%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 17% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DE
devguard · l3montree-dev
< 1.2.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42300
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42300
github.com
https://github.com/l3montree-dev/devguard/commit/6f38310bf93b2a63df3055038f4da82b1f4e6d9a
github.com
https://github.com/l3montree-dev/devguard/security/advisories/GHSA-2g9v-7mr5-fgjg
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