CVE-2026-42300
CVE-2026-42300 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-288.
Key facts
- Severity: Critical (CVSS 4.0 base score 9.3)
- EPSS exploit prediction: 0% (17th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-29704
- Weakness: CWE-288
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-42300?
- 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.
- How severe is CVE-2026-42300?
- CVE-2026-42300 has a CVSS 4.0 base score of 9.3, rated critical severity.
- Is CVE-2026-42300 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-42300?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-42300 have an EU (EUVD) identifier?
- Yes. CVE-2026-42300 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-29704.
- When was CVE-2026-42300 published?
- CVE-2026-42300 was published on 2026-05-12 and last updated on 2026-06-17.
References
- https://github.com/l3montree-dev/devguard/commit/6f38310bf93b2a63df3055038f4da82b1f4e6d9a
- https://github.com/l3montree-dev/devguard/security/advisories/GHSA-2g9v-7mr5-fgjg
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