{"id":"CVE-2026-45135","title":"caddy: github.com/caddyserver/caddy/v2: Caddy: Remote Code Execution via Unsafe Unicode Handling in FastCGI (CVE-2026-45135)","summary":"A flaw was found in Caddy. This vulnerability stems from unsafe handling of Unicode characters within the FastCGI component, specifically when processing request paths containing non-ASCII bytes. An attacker capable of placing content into…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"vendor","cwe":"CWE-1289","vendor":"Red Hat","product":"github.com/caddyserver/caddy/v2","affected":["github.com/caddyserver/caddy/v2 >= 2.7.0, < 2.11.3"],"patched":["github.com/caddyserver/caddy/v2 2.11.3"],"published":"2026-06-23","updated":"2026-09-23","sourceUpdated":"2026-09-23T18:36:50+00:00","source":"CSAF","sourceUrl":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45135.json","references":[{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45135.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-45135"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2491896"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-45135"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45135"},{"url":"https://github.com/caddyserver/caddy/security/advisories/GHSA-m675-2p33-xv9g"},{"url":"https://github.com/php/frankenphp/security/advisories/GHSA-3g8v-8r37-cgjm"},{"url":"https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38"},{"url":"https://github.com/caddyserver/caddy"}],"tags":["csaf","vex","red-hat","osv","go"],"epss":0.00676,"epssPercentile":0.52017,"aliases":["GHSA-m675-2p33-xv9g"],"ecosystem":"go","ingestedAt":"2026-07-20T19:04:14.882Z","slug":"CVE-2026-45135","body":"## Overview\n\nA flaw was found in Caddy. This vulnerability stems from unsafe handling of Unicode characters within the FastCGI component, specifically when processing request paths containing non-ASCII bytes. An attacker capable of placing content into files served via FastCGI can exploit this by crafting a malicious URL. This can mislead Caddy into executing non-script files as scripts, potentially leading to remote code execution.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · updated 2026-09-23 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45135.json)\n\n**caddy: github.com/caddyserver/caddy/v2: Caddy: Remote Code Execution via Unsafe Unicode Handling in FastCGI** — rated Important by Red Hat. Released 2026-06-23, updated 2026-09-23.\n\nNot affected:\n\n- Red Hat Hardened Images\n\n## Remediation\n\nRefer to the advisory for fix availability.\n\n## Package advisory (CVE-2026-45135)\n\nAffected packages:\n\n- `github.com/caddyserver/caddy/v2 >= 2.7.0, < 2.11.3`\n\nPatched in:\n\n- `github.com/caddyserver/caddy/v2 2.11.3`\n\nSource: https://osv.dev/vulnerability/GHSA-m675-2p33-xv9g","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}