High severity · published Jul 10, 2025
CVE-2025-53629
cpp-httplib Unbounded Memory Allocation in Chunked/No-Length Requests Vulnerability
7.5
CVSS
0.6%
EPSS
No
On KEV
Description
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.23.0, incoming requests using Transfer-Encoding: chunked in the header can allocate memory arbitrarily in the server, potentially leading to its exhaustion. This vulnerability is fixed in 0.23.0. NOTE: This vulnerability is related to CVE-2025-53628.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CP
cpp-httplib · yhirose
< 0.23.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-53629
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-53629
Patch
https://github.com/yhirose/cpp-httplib/commit/17ba303889b8d4d719be3879a70639ab653efb99
Not Applicable
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-j6p8-779x-p5pw
Exploit
https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-qjmq-h3cc-qv6w
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