Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L L N U H H N 8.1 .0029 21.7 —
AFFECTED Product Versions Fixed caddy < 2.11.4 – —
TIMELINE Jun 8 Reserved by GitHub_M Jun 23 EXPLOIT PUBLISHED — CVE-2026-52845 (caddyserver caddy). Public exploit reference added. Jun 23 Published (CNA: GitHub_M)
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through php_fastcgi, Caddy normalizes HTTP headers into CGI variables by replacing - with _. This lets a client send an underscore alias that survives the forward_auth delete step but becomes the same PHP/FastCGI variable. Result: a remote client can inject or sometimes override identity/group headers trusted by PHP/FastCGI applications behind Caddy. This vulnerability is fixed in 2.11.4.
| Date | Event | Detail |
|---|---|---|
| June 8, 2026 | Reserved | Reserved by GitHub_M |
| June 23, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-52845 (caddyserver caddy). Public exploit reference added. |
| June 23, 2026 | Published | Published (CNA: GitHub_M) |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| caddyserver | caddy | — | < 2.11.4 | — |
Authoritative record: CVE-2026-52845 at cve.org
Vendors: caddyserver
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-52845 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.