Quick answers
- Is CVE-2026-34441 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-34441 being exploited in the wild.
- How severe is CVE-2026-34441?
- Medium severity, with a CVSS score of 4.8, published 31 March 2026.
- Which products and versions are affected?
- Yhirose Cpp-Httplib < 0.40.0.
- Is there a fix for CVE-2026-34441?
- A patch was published on 2026-03-28: Version 0.40.0 released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-34441 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-34441?
- Check whether you run Yhirose Cpp-Httplib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
cpp-httplib is vulnerable to HTTP Request Smuggling (CWE-444). The root cause is twofold: first, the server's static file handler in `Server::routing()` returns a response for GET/HEAD requests without consuming the request body, leaving unread bytes on the TCP stream that the keep-alive loop interprets as a subsequent request. Second, the library fails to reject requests containing both 'Content-Length' and 'Transfer-Encoding' headers, violating RFC 9112 §6.3. An unauthenticated remote attacker can exploit these behaviors to embed arbitrary HTTP requests within the body of a GET request. This can lead to access control bypass, cache poisoning, or request hijacking. The issue is fixed in version 0.40.0.
Affected products
- yhirose cpp-httplib < 0.40.0
Timeline
- 2026-03-28: patched: Version 0.40.0 released
- 2026-03-31: disclosed: GitHub Advisory GHSA-jv63-rm9j-6jwc published
- 2026-03-31: advisory: CVE-2026-34441 published to NVD