CVE-2026-77281Caddy: rewrite placeholder re-expansion
- 6.5MediumCVSS base score
- 0.49%Exploitation in 30 daysEPSS · top 57% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 28 days later
· 28 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
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 57% of all CVEs (14 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.
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
References4
- 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)
- EUVD EUVD-2026-82474 (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://cveledger.app/cve/CVE-2026-77281)Record last updated .