Copyright © 2012 Red Hat, Inc. All rights reserved. Low 2026-07-14T10:00:00 SoupClientMessageIOHTTP2: libsoup3: libsoup: HTTP/2 GOAWAY frame parsing heap buffer over-read via invalid NUL-termination assumption 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CWE-125

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.

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.

This vulnerability poses a moderate impact to system confidentiality and availability for software implementations leveraging libsoup for HTTP/2 client or server communications. An unauthenticated network adversary can manipulate frame characteristics to force memory parsing out-of-bounds without requiring special system privileges or user interaction. While primarily resulting in a denial of service via a segmentation fault, the risk of data exposure from adjacent heap allocations places this as a notable security boundary failure within the protocol decoding stack. Red Hat would like to thank cavid for reporting this issue. The vulnerability requires debug logging to be enabled with the G_MESSAGES_DEBUG environment variable, e.g. G_MESSAGES_DEBUG=all or G_MESSAGES_DEBUG=libsoup-http2. Ensure this environment variable is not set. Red Hat Enterprise Linux 10 Fix deferred libsoup3 https://www.cve.org/CVERecord?id=CVE-2026-15712 https://nvd.nist.gov/vuln/detail/CVE-2026-15712 https://gitlab.gnome.org/GNOME/libsoup/-/work_items/540