PT-2026-1013 · Unknown+1 · Cpp-Httplib+1

Hritik14 · CVE-2026-21428 · Published 2026-01-01 · Updated 2026-03-26

Positive Technologies (AI Summary)

CVSS v4.0

8.7

High

Base vector

AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Name of the Vulnerable Software and Affected Versions cpp-httplib versions prior to 0.30.0

Description The write headers function in cpp-httplib does not properly validate user-supplied headers, specifically failing to check for carriage return (CR) and line feed (LF) characters. This allows attackers to inject additional headers, potentially modify the request body, and trigger a Server-Side Request Forgery (SSRF) attack. When used with servers supporting HTTP/1.1 pipelining, the risk of SSRF is increased. The vulnerable component is the write headers function.

Recommendations Update to version 0.30.0 or later.

Exploit

Fix

Weakness Enumeration

CWE-93

Related Identifiers

BDU:2026-00006

CVE-2026-21428

GHSA-WPC6-J37R-JCX7

OPENSUSE-SU-2026:10435-1

OPENSUSE-SU-2026:20733-1

SUSE-SU-2026:21599-1

Affected Products

Debian

Cpp-Httplib

References · 24

• 🔥 https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-wpc6-j37r-jcx7 · Exploit
• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21428.json · Exploit
• https://github.com/yhirose/cpp-httplib/commit/98048a033a532ff22320ce1d11789f8d5710dfcd · Patch
• https://osv.dev/vulnerability/openSUSE-SU-2026:10435-1 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-21428 · Security Note
• https://ubuntu.com/security/CVE-2026-21428 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-21428 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-21428 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2026-21428 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-00006 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-21428 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2026-21428 · Vendor Advisory
• https://github.com/yhirose/cpp-httplib/releases/tag/v0.30.0 · Note
• https://suse.com/security/cve/CVE-2026-28434 · Note
• https://suse.com/security/cve/CVE-2026-21428 · Note