---
id: CVE-2026-55706
title: >-
  sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows
  authentication bypass via certain zero values for lengths.
summary: >-
  sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows
  authentication bypass via certain zero values for lengths.
severity: medium
cvss: 5.8
cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L'
cwe:
  - CWE-1284
vendor: openbsd
product: openbsd
affected:
  - openbsd <= 7.6
published: '2026-06-17'
updated: '2026-07-13'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-55706'
references:
  - url: 'https://blog.argus-systems.ai/blog/openbsd-pap-27-year-auth-bypass.html'
    label: cve@mitre.org
  - url: >-
      https://github.com/openbsd/src/commit/076e2b1c1fc4ac0883a72d3544131ad5cee7adf8
    label: cve@mitre.org
  - url: 'https://www.openwall.com/lists/oss-security/2026/06/16/9'
    label: cve@mitre.org
  - url: 'https://blog.argus-systems.ai/blog/poc-001-pap-bypass.py'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
epss: 0.00344
epssPercentile: 0.25136
ingestedAt: '2026-07-13T14:27:26.762Z'
---

## Overview

sppp_pap_input in sys/net/if_spppsubr.c in OpenBSD before 076e2b1 allows authentication bypass via certain zero values for lengths.

## Affected

- `openbsd <= 7.6`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.