CVE-2026-77281Caddy: rewrite placeholder re-expansion
Updated under an hour ago ()
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It affects caddyserver caddy. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
- Weakness (CWE)
- CWE-94, CWE-178, CWE-770
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Awaiting Analysis
- Record last updated
- Sep 18, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
caddyserver caddy caddyserver:caddy (from the name) | before 2.11.4 | CNA record |
References
- https://github.com/caddyserver/caddy/security/advisories/GHSA-j8px-rmrx-76h9x-refsource-confirm
- https://github.com/caddyserver/caddy/pull/7761x-refsource-misc
- https://github.com/caddyserver/caddy/commit/176b043b0104cee3f894023cd5a598ac29e404bbx-refsource-misc
- https://github.com/caddyserver/caddy/releases/tag/v2.11.4x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.