CVE-2026-22776 cpp-httplib vulnerable to a denial of service (DOS) using a zip bomb
Attackers can cause denial of service in applications using cpp-httplib by sending compressed requests that expand to consume excessive memory.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-22776?
CVE-2026-22776 is a high-severity denial of service vulnerability in yhirose cpp-httplib, published on 12 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-409
Which versions are affected by CVE-2026-22776?
It affects 1 product.
Products include Yhirose Cpp-Httplib.
How do I fix CVE-2026-22776?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-22776 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-22776 exists.
Other vulnerabilities in yhirose cpp-httplib
- CVE-2025-66570 cpp-httplib Untrusted HTTP Header Handling: Internal Header Shadowing (REMOTE*/LOCAL*)
- CVE-2026-45372 cpp-httplib: HTTP header value percent-decoding in server-side `parse_header` enables CRLF injection
- CVE-2026-46527 Null dereference in cpp-httplib
- CVE-2026-32627 cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy
- CVE-2026-21428 cpp-httplib has CRLF injection in http headers
Sources
Also known as DEBIAN-CVE-2026-22776, GHSA-h934-98h4-j43q, UBUNTU-CVE-2026-22776.