CVE-2026-32627
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 8.1 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.18% probability · 8th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-295
- Affected
- yhirose/cpp-httplib
- Source
- security-advisories@github.com
References
- https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-c3h8-fqq4-xm4gExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.