CVE-2026-21428
highpriority · track · 30EPSS 0.004 · 34 %ileDEEURUUSEPSS · scored 2026-10-27
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.0, the ``write_headers`` function does not check for CR & LF characters in user supplied headers, allowing untrusted header value to escape header lines. This vulnerability allows attackers to add extra headers, modify request body unexpectedly & trigger an SSRF attack. When combined with a server that supports http1.1 pipelining (springboot, python twisted etc), this can be used for server side request forgery (SSRF). Version 0.30.0 fixes this issue.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- Fixedcpp-httplib-devel-0:0.38.0-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcpp-httplib-devel-0:0.38.0-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcpp-httplib-devel-0:0.38.0-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedcpp-httplib-devel-0:0.38.0-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedlibcpp-httplib0_38-0:0.38.0-1.1.aarch64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedlibcpp-httplib0_38-0:0.38.0-1.1.ppc64le as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedlibcpp-httplib0_38-0:0.38.0-1.1.s390x as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
- Fixedlibcpp-httplib0_38-0:0.38.0-1.1.x86_64 as component of openSUSE Tumbleweedsuse_csaf
To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or "zypper patch".
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–8.7
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- openSUSE-SU-2026:10435-1cpp-httplib-devel-0.38.0-1.1 on GA media2026-03-26csaf · suse_csafDE
cpp-httplib-devel-0.38.0-1.1 on GA media
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://github.com/yhirose/cpp-cnnvd
- https://github.com/yhirose/cpp-httplib/releasesPatchcnnvd
- https://vigilance.fr/vulnerability/cpp-cnnvd
- https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcdenisa_euvd
- https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0enisa_euvd
- https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-wpc6-j37r-jcx7enisa_euvd
- https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcdPatchnvd
- https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0ProductRelease Notesnvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan