Executive brief
A security vulnerability exists in GLib, a fundamental software library used by many Linux applications to handle communication between different programs. An attacker can send a continuous stream of data to a service using this library, forcing it to consume all available system memory and processor power. This can cause the affected application or the entire system to crash or become unresponsive, leading to a denial of service.
Technical details
A resource exhaustion vulnerability (CWE-770) exists in the GDBusServer implementation within GLib's GIO module. The root cause is located in the `_my_g_input_stream_read_line_safe()` function in `gio/gdbusauth.c`, which reads D-Bus SASL authentication commands one byte at a time into a GString until a CRLF terminator is encountered, without enforcing a maximum line length. An unauthenticated local or remote attacker can exploit this by sending an excessively long, unterminated AUTH line (e.g., AUTH EXTERNAL followed by infinite data). This causes the target process to allocate memory until it either aborts due to a GLib allocation failure or is terminated by the operating system's out-of-memory (OOM) killer. The vulnerability is reachable pre-authentication, meaning no valid credentials are required to trigger the crash.
Affected products
- GNOME GLib 2.26.0 to 2.80.x (starting from 2.25.8)
- Red Hat Red Hat Enterprise Linux 6
- Red Hat Red Hat Enterprise Linux 7
- Red Hat Red Hat Enterprise Linux 8
- Red Hat Red Hat Enterprise Linux 9
- Red Hat Red Hat Enterprise Linux 10
Timeline
- 2026-07-13: other: Initial bug report in Red Hat Bugzilla
- 2026-07-20: disclosed: Public disclosure of CVE-2026-15588