CVE-2026-30851
Caddy forward_auth header handling allows identity injection and privilege escalation.
Is CVE-2026-30851 being exploited?
Not confirmed. CVE-2026-30851 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-30851?
CVE-2026-30851 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-30851?
Yes. A fix has been recorded for CVE-2026-30851. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-30851 affect?
CVE-2026-30851 affects Caddy Server (versions 2.10.0–2.11.1). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-30851?
Upgrade to 2.11.2+ to mitigate.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker can spoof identities via unstripped forward_auth headers, enabling privilege escalation on vulnerable Caddy servers.
Immediate action required
- affected>= 2.10.0 and < 2.11.2
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.