Is CVE-2026-45372 actively exploited?

No active exploitation of CVE-2026-45372 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-45372 be exploited remotely?

Yes. CVE-2026-45372 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-45372?

CVE-2026-45372 has a CVSS score of 9.9 (CRITICAL).

HOME VULNERABILITIESCVE-2026-45372

CRITICAL

CVE-2026-45372

CWE-93Published: May 29, 2026· Updated: Jun 1, 2026

9.9

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.9th

Official 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.

NVD Source

Risk Analysis

cpp-httplib versions prior to 0.44.0 are vulnerable to a critical flaw where percent-encoded characters in HTTP header values are improperly handled. This can lead to the expansion of encoded newlines, potentially resulting in HTTP header injection or other related attacks. This is a critical vulnerability with a CVSS score of 9.9.

No public exploit is currently known for this vulnerability. It is remotely exploitable due to the network attack vector and low attack complexity.

Recommended Action

Upgrade cpp-httplib to version 0.44.0 or later to address this vulnerability. Ensure that applications using cpp-httplib are updated to the secure version.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2026-45372 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 9.9.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.