CVE-2026-123205

Received Received - Intake

Heap Buffer Overflow in accel-ppp TCP Logging

Publication date: 2026-11-05

Last updated on: 2026-11-05

Assigner: VulnCheck

Description

accel-ppp before 1.15.0 contains a heap buffer overflow vulnerability in the tcp, syslog and pgsql log targets that allows unauthenticated remote peers to overflow fixed heap buffers by producing log lines exceeding LOG_MAX_SIZE. Attackers within client-ip-range can send an L2TP Start-Control-Connection-Request with many string AVPs when verbose logging is enabled to corrupt heap memory and crash the daemon.

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Meta Information

Published

2026-11-05

Last Modified

2026-11-05

Generated

2026-11-06

AI Q&A

2026-11-06

EPSS Evaluated

N/A

NVD

CVE-2026-123205

EUVD

EUVD-2026-117650

Affected Vendors & Products

Vendor	Product	Version / Range
accel-ppp	accel-ppp	0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This vulnerability is a heap-based buffer overflow in accel-ppp versions before 1.15.0 affecting the tcp, syslog, and pgsql logging targets. When verbose logging is enabled, unauthenticated remote attackers within the client IP range can send specially crafted L2TP packets with many string AVPs to generate oversized log lines exceeding LOG_MAX_SIZE. This corrupts heap memory and crashes the daemon.

Detection Guidance

To detect this vulnerability, check if your accel-ppp version is below 1.15.0. Run 'accel-pppd -v' or check package versions. Monitor logs for crashes in log_tcp, log_syslog, or log_pgsql modules. Inspect network traffic for L2TP Start-Control-Connection-Request packets with excessive string AVPs when verbose logging is enabled.

Impact Analysis

An attacker could exploit this to crash the accel-ppp daemon, causing service disruption. The heap corruption might allow limited memory manipulation, though remote code execution is not confirmed. Downtime and potential loss of logging data are primary risks.

Mitigation Strategies

Upgrade accel-ppp to version 1.15.0 or later immediately. Disable verbose logging if enabled. Restrict client IP ranges to trusted networks. Monitor for crashes or unusual log behavior. Apply patches from the official repository if upgrading is not immediately possible.

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