CVE-2026-77281
Caddy: rewrite placeholder re-expansion
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L |
| NVDNVD · Awaiting Analysis | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L |
- EPSS (exploitation in 30 days)
- 0.49% · top 58% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
- CWE-94: Improper Control of Generation of Code ('Code Injection') (opens in a new tab)All about CWE-94 and its CVEs
- CWE-178: Improper Handling of Case Sensitivity (opens in a new tab)All about CWE-178 and its CVEs
- CWE-770: Allocation of Resources Without Limits or Throttling (opens in a new tab)All about CWE-770 and its CVEs
Affected products
- affected < 2.11.4
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- Gogithub.com/caddyserver/caddy/v2GHSA-j8px-rmrx-76h9 (opens in a new tab)
References (4)
- https://github.com/caddyserver/caddy/security/advisories/GHSA-j8px-rmrx-76h9 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/caddyserver/caddy/pull/7761 (opens in a new tab)x_refsource_MISC
- https://github.com/caddyserver/caddy/commit/176b043b0104cee3f894023cd5a598ac29e404bb (opens in a new tab)x_refsource_MISC
- https://github.com/caddyserver/caddy/releases/tag/v2.11.4 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-j8px-rmrx-76h9 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-77281)Record last updated .