CVE-2026-77281

medium

Description

Caddy is an extensible server platform that uses TLS by default. In version 2.11.3 and earlier, three configuration-dependent weaknesses affect the handler and placeholder layer. In modules/caddyhttp/rewrite/rewrite.go, Rewrite.Rewrite() can pass attacker-controlled replacement bytes through buildQueryString for a second placeholder expansion when a rewrite URI ends with a literal question mark, allowing injected environment or request-variable placeholders to disclose data and, when the file provider is registered, allowing injected file placeholders to disclose readable files. The issue is fixed in version 2.11.4.

References

https://github.com/caddyserver/caddy/security/advisories/GHSA-j8px-rmrx-76h9

https://github.com/caddyserver/caddy/releases/tag/v2.11.4

https://github.com/caddyserver/caddy/pull/7761

https://github.com/caddyserver/caddy/commit/176b043b0104cee3f894023cd5a598ac29e404bb

Details

Source: Mitre, NVD

Published: 2026-09-17

Updated: 2026-09-18

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

Severity: Medium

EPSS

EPSS: 0.0036