{"id":"CVE-2026-77341","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-77341","generatedAt":"2026-10-28T05:01:38.064Z","title":"In version 0.49.0, the chunked-response trailer output path writes trailer header names and values directly to the socket without validating them, allowing CRLF sequences in a trailer field to inject additional headers or split the HTTP response.","description":"cpp-httplib is a C++ header-only HTTP/HTTPS library. In version 0.49.0, the chunked-response trailer output path writes trailer header names and values directly to the socket without validating them, allowing CRLF sequences in a trailer field to inject additional headers or split the HTTP response. Unlike every other header-writing path in the library, the trailer-writing code applies none of the field-name and field-value checks that reject carriage return and line feed, so an application that places attacker-influenced data into a chunked response trailer emits attacker-controlled CRLF onto the wire. This enables HTTP response splitting, letting an attacker forge response headers or inject a second response. This issue is fixed in version 0.50.0.","published":"2026-08-28T00:18:16.000Z","lastModified":"2026-09-09T21:09:13.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-93","CWE-113"],"affected":[],"epss":{"score":0.00461,"percentile":0.39787,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.46%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/yhirose/cpp-httplib/commit/568d434e72fc51729d0ad33abffb181e5f7a453d","source":"security-advisories@github.com"},{"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c","source":"security-advisories@github.com"},{"url":"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-2r2h-jc8w-w66c","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-77341","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}