# CVE-2026-123205: accel-ppp before 1.15.0 Heap-based Buffer Overflow via oversized log lines in log_tcp/log_syslog/log_pgsql

Status: published. Published: 2026-11-05. Updated: 2026-11-09.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/accel-ppp/accel-ppp/pull/374
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: VulnCheck) — https://github.com/accel-ppp/accel-ppp/commit/58e399400c4ef4b71472ab7c2c71c54a677a05a8

## Affected products and versions

- accel-ppp / accel-ppp (accel-ppp/accel-ppp): ≥ 0; < 1.15.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.3 (high); 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; source: CNA: VulnCheck

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H; source: CNA: VulnCheck

- CVSS 4.0: 8.3 (high); 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X; source: NVD: disclosure@vulncheck.com

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H; source: NVD: disclosure@vulncheck.com

- CISA KEV: No listing in collected sources

- EPSS: 0.42% as of 2026-11-09; percentile 36.34%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-122

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/accel-ppp/accel-ppp/pull/374 (CNA: VulnCheck; issue-tracking, patch)

- https://github.com/accel-ppp/accel-ppp/commit/58e399400c4ef4b71472ab7c2c71c54a677a05a8 (CNA: VulnCheck; patch)

- https://github.com/accel-ppp/accel-ppp/releases/tag/1.15.0 (CNA: VulnCheck; release-notes)

- https://github.com/accel-ppp/accel-ppp/blob/048d31cb446879e0d1a1471b4ab99135a92bf289/accel-pppd/logs/log_tcp.c#L55-L67 (CNA: VulnCheck; technical-description)

- 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 (CNA: VulnCheck; third-party-advisory)

- https://github.com/accel-ppp/accel-ppp/blob/048d31cb446879e0d1a1471b4ab99135a92bf289/accel-pppd/logs/log_tcp.c#L55-L67 (disclosure@vulncheck.com)

- https://github.com/accel-ppp/accel-ppp/commit/58e399400c4ef4b71472ab7c2c71c54a677a05a8 (disclosure@vulncheck.com)

- https://github.com/accel-ppp/accel-ppp/pull/374 (disclosure@vulncheck.com)

- https://github.com/accel-ppp/accel-ppp/releases/tag/1.15.0 (disclosure@vulncheck.com)

- 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 (disclosure@vulncheck.com)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-123205; retrieved 2026-11-09; source updated 2026-11-09

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-123205; retrieved 2026-11-06; source updated 2026-11-05

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-123205; retrieved 2026-11-09; source updated Not reported

Revision: 3df717e59ab6559499e423ff7d2500a780c6d74ac4d358118cd04a7de2302ead

Canonical: https://y2.dev/cve/CVE-2026-123205

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