CVE-2026-77341: medium-severity vulnerability in yhirose cpp-httplib
cpp-httplib: CRLF injection via unvalidated HTTP trailer headers in chunked response writing
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.5%
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.
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
Affected products
yhirose · cpp-httplibRelated CVEs — yhirose cpp-httplib
In the same product, most dangerous first.
CVE-2026-29076MEDIUMcpp-httplib: Stack Overflow Denial of Service (DoS) via std::regex in multipart filename parsingEPSS 0.7%CVE-2025-46728HIGHcpp-httplib has Unbounded Memory Allocation in Chunked/No-Length RequestsEPSS 0.7%CVE-2025-53629HIGHcpp-httplib Unbounded Memory Allocation in Chunked/No-Length Requests VulnerabilityEPSS 0.6%CVE-2025-53628MEDIUMcpp-httplib does not limit the length of a lineEPSS 0.5%CVE-2026-31870HIGHcpp-httplib Affected by Remote Process Crash via Malformed Content-Length Response HeaderEPSS 0.5%CVE-2025-52887HIGHcpp-httplib has unlimited number of http header fields, which causes memory leakEPSS 0.5%