Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
yhirose cpp-httplib — cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N N C L H L 9.9 .0029 22.1 —
AFFECTED
Product Versions Fixed
cpp-httplib < 0.44.0 – —
TIMELINE
May 12 Reserved by GitHub_M
May 29 EXPLOIT PUBLISHED — CVE-2026-45372 (yhirose cpp-httplib). Public exploit reference added.
May 29 Published (CNA: GitHub_M)
Description
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| May 12, 2026 | Reserved | Reserved by GitHub_M |
| May 29, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-45372 (yhirose cpp-httplib). Public exploit reference added. |
| May 29, 2026 | Published | Published (CNA: GitHub_M) |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| yhirose | cpp-httplib | — | < 0.44.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-45372 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.