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.
References (2)
Core 2
Core References
Exploit, Vendor Advisory x_refsource_confirm
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h934-98h4-j43q
Scores
CVSS v3
7.5
EPSS
0.0008
EPSS Percentile
23.5%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-409
Status
published
Products (1)
yhirose/cpp-httplib
< 0.30.1
Published
Jan 12, 2026
Tracked Since
Feb 18, 2026