Microsoft Security Response Center guidance
Vendor revision: Sep 24, 2026Release Notes
Vulnerability intelligence
CVE-2026-15712 and is rated Medium severity with a CVSS score of 5.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
Release Notes
A heap buffer over-read vulnerability was discovered in libsoup's (versions: libsoup 3.0 to 3.7.0) HTTP/2 connection tracking framework. When the library processes an HTTP/2 GOAWAY frame, it improperly handles the "Additional Debug Data" payload by assuming the data stream is a safely NUL-terminated C-string.
Because the parser lacks strict length-boundary verification before reading this data, a remote, unauthenticated attacker can intentionally send a malformed GOAWAY frame missing the appropriate null delimiter. This causes the library to read past the end of the allocated buffer, triggering an application crash that results in a denial of service (DoS), or potentially exposing fragments of memory contents.
Source: NVD