D-Bus select() FD OOB Write DoS
CVE-2026-128885 Published on November 13, 2026
Dbus: stack out-of-bounds write in dbus _dbus_poll() select() fallback when file descriptor exceeds fd_setsize
A flaw was found in D-Bus. In configurations where the daemon falls back to using the Unix select() mechanism for event monitoring, it does not verify whether file descriptor numbers exceed allocated limits. A local attacker can exploit this flaw by opening a large number of concurrent connections to trigger an out-of-bounds write on the stack. This can cause the daemon to crash, resulting in a Denial of Service (DoS).
Vulnerability Analysis
CVE-2026-128885 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. Public availability of a proof of concept (POC) exploit exists for CVE-2026-128885. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Reported to Red Hat.
Made public. 115 days later.
Weakness Type
What is a Stack Overflow Vulnerability?
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CVE-2026-128885 has been classified to as a Stack Overflow vulnerability or weakness.
Products Associated with CVE-2026-128885
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Affected Versions
Red Hat Enterprise Linux 10:Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.