CVE-2026-34253: vorbis-tools Buffer Overflow Vulnerability

CVE-2026-34253 Overview

CVE-2026-34253 is a buffer underflow vulnerability in the ogg123 utility distributed with the vorbis-tools 1.4.3 package. The flaw resides in the remotethread function within remote.c, which handles the remote control interface. When the function processes malformed input, a stack buffer underflow occurs, corrupting memory adjacent to the buffer.

The vulnerability is tracked under [CWE-124] (Buffer Underwrite). Successful exploitation can crash the application and, under specific conditions, allow arbitrary code execution within the process context of ogg123.

Critical Impact
Attackers leveraging the remote control interface can trigger memory corruption that results in denial of service and potential code execution on systems running vulnerable builds of vorbis-tools 1.4.3.

Affected Products

vorbis-tools 1.4.3 — ogg123 utility
Linux distributions packaging vorbis-tools 1.4.3
Applications and scripts invoking ogg123 with its remote control interface enabled

Discovery Timeline

2026-05-15 - CVE-2026-34253 published to NVD
2026-05-18 - Last updated in NVD database

Technical Details for CVE-2026-34253

Vulnerability Analysis

The ogg123 command-line audio player ships with a remote control feature implemented in remote.c. The remotethread function reads commands from an input source and parses them into a fixed-size stack buffer. Improper boundary handling on parsed input allows a write to occur before the start of the buffer, producing a stack buffer underwrite.

Memory below the buffer holds saved registers, return addresses, and local variables for the calling frame. Corrupting these structures yields immediate process termination at minimum. With controlled input, an attacker can manipulate execution flow once the underwritten data is consumed by the function epilogue.

The issue affects a network-reachable code path because the remote control mechanism accepts input that can originate from external sources. Combined with no authentication on the remote interface, the vulnerability provides a low-complexity path to memory corruption.

Root Cause

The root cause is the absence of strict bounds enforcement around an index or pointer used to write into a stack-allocated buffer in remotethread. The implementation does not validate that the computed write position remains within the buffer's allocated region. Source code referenced at remote.c line 153 shows the affected logic.

Attack Vector

An attacker delivers crafted input through the ogg123 remote control channel. Because the attack vector is network-accessible with low complexity and no privileges or user interaction required, automated exploitation against exposed instances is feasible. Successful exploitation impacts integrity and availability of the targeted process.

No verified public proof-of-concept code is associated with this CVE. Technical details are available in the GitLab work item #2332 and the vorbis-tools 1.4.3 source archive.

Detection Methods for CVE-2026-34253

Indicators of Compromise

Unexpected crashes or segmentation faults from ogg123 processes recorded in system logs or core dump directories
Inbound network connections or local pipe activity targeting ogg123 remote control sockets on hosts not configured for such use
Presence of vorbis-tools version 1.4.3 binaries on production systems where audio playback is not a required function

Detection Strategies

Inventory hosts for installed vorbis-tools packages using package managers (dpkg -l vorbis-tools, rpm -q vorbis-tools) and flag version 1.4.3
Monitor for ogg123 process invocations that include remote control flags such as -R and correlate with parent process and command line
Review crash telemetry for ogg123 faults occurring inside remotethread frames in stack traces

Monitoring Recommendations

Forward process execution and crash events from Linux endpoints to a centralized logging platform for analysis
Alert on ogg123 execution outside of expected media-handling workflows, particularly on servers
Track outbound and inbound socket activity associated with ogg123 to identify abuse of the remote interface

How to Mitigate CVE-2026-34253

Immediate Actions Required

Identify and inventory all systems running vorbis-tools 1.4.3, prioritizing servers, build agents, and media processing pipelines
Disable or remove the ogg123 utility on hosts where it is not required
Restrict invocation of ogg123 with remote control flags through application allowlists or wrapper scripts

Patch Information

At the time of publication, fix status is tracked upstream at GitLab work item #2332. Apply distribution-provided updates to vorbis-tools once available. Monitor the Xiph.Org vorbis-tools repository for tagged releases beyond 1.4.3.

Workarounds

Avoid launching ogg123 with the remote control mode (-R) enabled until a patched version is installed
Run ogg123 under a dedicated low-privilege account with seccomp or AppArmor/SELinux profiles to limit blast radius of memory corruption
Block network exposure of any local socket or named pipe used by the ogg123 remote interface using host-based firewall rules

bash

# Configuration example: locate vulnerable installs and disable execution
find / -type f -name 'ogg123' 2>/dev/null
dpkg -l | grep vorbis-tools
chmod 000 /usr/bin/ogg123