Vulnerability · Published Mar 13, 2026 · Assigned by GitHub_M

CVE-2026-32627cpp-httplib has a Silent TLS Certificate Verification Bypass on HTTPS Redirect via Proxy

High 8.7

In plain English

A high-severity improper certificate validation in cpp-httplib from yhirose. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.7High

Exploit odds (30 days)0.2%top 91.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.37.2, when a cpp-httplib client is configured with a proxy and set_follow_location(true), any HTTPS redirect it follows will have TLS certificate and hostname verification silently disabled on the new connection. The client will accept any certificate presented by the redirect target — expired, self-signed, or forged — without raising an error or notifying the application. A network attacker in a position to return a redirect response can fully intercept the follow-up HTTPS connection, including any credentials or session tokens in flight. This vulnerability is fixed in 0.37.2.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	cpp-httplib	no fix listed	DEBIAN-CVE-2026-32627
Debian:13	cpp-httplib	no fix listed	DEBIAN-CVE-2026-32627
Debian:14	cpp-httplib	0.41.0+ds-3	DEBIAN-CVE-2026-32627
Ubuntu:25.10	cpp-httplib	no fix listed	UBUNTU-CVE-2026-32627
Ubuntu:26.10	cpp-httplib	no fix listed	UBUNTU-CVE-2026-32627

Affected products (as reported)

Vendor	Product	Versions
yhirose	cpp-httplib	< 0.37.2

Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N

References

https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-c3h8-fqq4-xm4g x_refsource_CONFIRM