CVE-2026-14330 Overview
CVE-2026-14330 affects the PulseAudio protocol server, which contains multiple unbounded alloca() calls. The flaw is classified under [CWE-770] Allocation of Resources Without Limits or Throttling. A local authenticated attacker can trigger stack allocations of attacker-controlled size, exhausting the process stack and causing the audio server to crash.
The issue is tracked in the Red Hat CVE-2026-14330 Advisory and Red Hat Bug Report #2495907. No exploits are publicly available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.
Critical Impact
A local user can crash the PulseAudio protocol server through stack exhaustion, disrupting audio services and any dependent applications on the affected host.
Affected Products
- PulseAudio protocol server (upstream)
- Red Hat Enterprise Linux distributions shipping PulseAudio (see vendor advisory)
- Downstream Linux distributions packaging affected PulseAudio releases
Discovery Timeline
- 2026-07-01 - CVE-2026-14330 published to NVD
- 2026-07-01 - Last updated in NVD database
Technical Details for CVE-2026-14330
Vulnerability Analysis
The PulseAudio protocol server uses the alloca() function in multiple code paths to allocate memory on the stack. These allocations occur without validating the requested size against reasonable bounds. When a client submits a protocol message that influences the allocation size, the server may attempt to allocate an arbitrarily large region on its stack.
Because alloca() does not return an error on failure, an oversized allocation moves the stack pointer past the guard page. The subsequent memory access crashes the process with SIGSEGV. This results in loss of audio functionality until the service restarts.
The attack requires local access and low privileges. No user interaction is needed. Confidentiality and integrity are not affected. Availability impact is high.
Root Cause
The root cause is the unrestricted use of alloca() with sizes derived from untrusted protocol input. alloca() bypasses the normal heap allocator and provides no mechanism to signal allocation failure. Any code path where a client-controlled length feeds into alloca() without a maximum bound check is a candidate for this crash condition.
Attack Vector
An attacker with a local account and access to the PulseAudio socket sends a crafted protocol message specifying an oversized buffer length. The server invokes alloca() with that length, expanding the stack past its guard page. The process aborts, and audio delivery halts for all sessions on that server.
The vulnerability requires an authenticated local session with permission to connect to the PulseAudio socket. Remote exploitation is not possible in the default configuration.
Refer to the Red Hat Bug Report #2495907 for additional technical detail on the affected code paths.
Detection Methods for CVE-2026-14330
Indicators of Compromise
- Repeated abnormal terminations of the pulseaudio process, particularly with SIGSEGV in stack frames near protocol-handling functions
- systemd or session manager logs showing repeated PulseAudio service restarts
- Core dumps of pulseaudio referencing large alloca()-driven stack frames
Detection Strategies
- Monitor process exit codes and crash signals for pulseaudio across managed Linux endpoints
- Correlate PulseAudio crashes with client connection events on the local UNIX socket to identify potentially malicious callers
- Review audit logs for unusual local users establishing PulseAudio sessions on multi-user or shared systems
Monitoring Recommendations
- Enable core dump collection for pulseaudio to support post-crash forensics
- Alert on more than one PulseAudio crash per host within a short interval
- Track package versions of pulseaudio across the fleet to identify unpatched hosts
How to Mitigate CVE-2026-14330
Immediate Actions Required
- Apply vendor-supplied PulseAudio updates as soon as they are published in your distribution's channels
- Inventory hosts running PulseAudio, prioritizing multi-user systems, jump hosts, and shared workstations
- Restrict local shell and session access on affected systems to trusted users only
Patch Information
Consult the Red Hat CVE-2026-14330 Advisory for the authoritative list of fixed package versions. Downstream distributions will publish updated pulseaudio packages that add size checks on protocol-driven alloca() calls or replace them with bounded heap allocations. Rebuild any downstream packages that statically link against affected PulseAudio libraries.
Workarounds
- Limit access to the PulseAudio UNIX socket using filesystem permissions on shared systems
- Disable network-mode PulseAudio if it is not required in your environment
- Configure session managers to restart pulseaudio automatically to reduce availability impact from repeated crashes
# Configuration example
# Restrict PulseAudio socket access to the owning user only
chmod 700 /run/user/$(id -u)/pulse
# Disable network access module in /etc/pulse/default.pa
# (comment out the following lines if present)
# load-module module-native-protocol-tcp
# load-module module-esound-protocol-tcp
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
