Vulnerability · Published Jan 12, 2026 · Assigned by GitHub_M

CVE-2026-22776cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb

High 8.7

In plain English

A high-severity security flaw in cpp-httplib from yhirose. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.4%top 64.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to version 0.30.1, a Denial of Service (DoS) vulnerability exists in cpp-httplib due to the unsafe handling of compressed HTTP request bodies (Content-Encoding: gzip, br, etc.). The library validates the payload_max_length against the compressed data size received from the network, but does not limit the size of the decompressed data stored in memory.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12cpp-httplibno fix listedDEBIAN-CVE-2026-22776
Debian:13cpp-httplibno fix listedDEBIAN-CVE-2026-22776
Debian:14cpp-httplib0.41.0+ds-3DEBIAN-CVE-2026-22776
Ubuntu:25.10cpp-httplibno fix listedUBUNTU-CVE-2026-22776
Ubuntu:26.10cpp-httplibno fix listedUBUNTU-CVE-2026-22776

Affected products (as reported)

VendorProductVersions
yhirose cpp-httplib < 0.30.1

Weakness: CWE-409 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

References