Use After Free in Yhirose Cpp-Httplib
CVE-2026-77358
cpp-httplib is a C++ header-only HTTP/HTTPS library. In versions 0.33.0 through 0.50.0, the TLS-enabled WebSocket client frees the TLS session before closing the WebSocket that still uses it, producing a use-after-free. In WebSocketClient::shutdown_and_close the SSL object is freed and the pointer cleared, but the subsequent WebSocket close still sends a close frame through the SSL socket stream, which holds a raw copy of the now-dangling session pointer and reads from and writes to the freed memory. The same freed-then-used ordering is reachable through the client's destructor and its connect path, so ordinary teardown of a secure WebSocket connection triggers the defect. This issue is fixed in version 0.50.1.
Vulnerability class: Use-After-Free
Published · last modified .
EPSS exploit prediction
EPSS: 0.004 (36.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002
Affected products
- Yhirose Cpp-Httplib — versions >= 0.33.0, < 0.50.