p PatchFirst

CVE-2026-49943

CVE-2026-49943

This page contains facts from public vulnerability sources. Check the original advisory before updating.

CZ.NIC BIRD Internet Routing Daemon through 2.19.0 contains a stack-based buffer overflow in the BGP AS_PATH mask matching implementation in nest/a-path.c. The as_path_match() function uses a fixed-size stack array of 2048 + 1 pm_pos entries, while parse_path() expands AS_PATH segments from a received BGP UPDATE without enforcing a corresponding capacity limit. When RFC 8654 BGP Extended Messages are enabled and a BIRD filter evaluates an AS path mask expression such as "bgp_path ~ [= ... =]", an established BGP peer can send a long AS_PATH containing more than 2048 expanded ASNs. This causes parse_path()/as_path_match() to write beyond the fixed stack buffer, resulting in a crash of the daemon. NOTE: reportedly, the Supplier's position is that a fix is not being prioritized because all network operators should already be rejecting routes with unusually long attributes.

CVSS 6.3 · Medium · EPSS 0.4%

Published
Updated

Stack: system

Affected products and versions

  • bird

    Versions
    • ≥ 0, ≤ 2.19.0: Affected (semver)

    No fix published

  • bird Debian:12

    Versions
    • 1.6.8-2.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Debian:12

    Versions
    • 2.0.12-7
    • 2.14-1
    • 2.15-1
    • 2.15.1-1
    • 2.15.1-1.1
    • 2.16-1
    • 2.16.1-1
    • 2.17-1
    • 2.17.1-1
    • 2.17.2-1
    • 2.17.3-1
    • 2.17.3-2
    • 2.18-1
    • 2.18.1-1
    • 2.19.0-1
    • 2.19.1-1
    • 2.19.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Debian:13

    Versions
    • 2.17.1-1
    • 2.17.1-1+deb13u1
    • 2.17.1-1+deb13u2
    • 2.17.2-1
    • 2.17.3-1
    • 2.17.3-2
    • 2.17.5-0+deb13u1
    • 2.18-1
    • 2.18.1-1
    • 2.19.0-1
    • 2.19.1-1
    • 2.19.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Debian:14

    Versions
    • 2.17.1-1
    • 2.17.2-1
    • 2.17.3-1
    • 2.17.3-2
    • 2.18-1
    • 2.18.1-1
    • 2.19.0-1
    • 2.19.1-1
    • 2.19.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird3 Debian:13

    Versions
    • 3.1.0-1
    • 3.1.4-1
    • 3.1.5-1
    • 3.1.5-2
    • 3.1.7-0+deb13u1
    • 3.2.0-1
    • 3.2.1-1
    • 3.3.0-1
    • 3.3.0-1~bpo13+1
    • 3.3.1-1
    • 3.3.2-1
    • 3.3.2-1~bpo13+1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird3 Debian:14

    Versions
    • 3.1.0-1
    • 3.1.4-1
    • 3.1.5-1
    • 3.1.5-2
    • 3.2.0-1
    • 3.2.1-1
    • 3.3.0-1
    • 3.3.0-1~bpo13+1
    • 3.3.1-1
    • 3.3.2-1
    • 3.3.2-1~bpo13+1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird Ubuntu:16.04:LTS

    Versions
    • 1.5.0-4
    • 1.5.0-4build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird Ubuntu:18.04:LTS

    Versions
    • 1.6.3-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird Ubuntu:20.04:LTS

    Versions
    • 1.6.7-1
    • 1.6.8-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:20.04:LTS

    Versions
    • 2.0.5-1
    • 2.0.7-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird Ubuntu:22.04:LTS

    Versions
    • 1.6.8-2.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:22.04:LTS

    Versions
    • 2.0.7-4.1
    • 2.0.8-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird Ubuntu:24.04:LTS

    Versions
    • 1.6.8-2.1
    • 1.6.8-2.1build1
    • 1.6.8-2.1build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:24.04:LTS

    Versions
    • 2.0.12-7
    • 2.14-1
    • 2.14-1build1
    • 2.14-1build2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:25.10

    Versions
    • 2.16.1-1
    • 2.17-1
    • 2.17.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird3 Ubuntu:25.10

    Versions
    • 3.1.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:26.10

    Versions
    • 2.18-1
    • 2.18.1-1
    • 2.19.0-1
    • 2.19.1-1
    • 2.19.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird3 Ubuntu:26.10

    Versions
    • 3.2.0-1
    • 3.2.1-1
    • 3.3.0-1
    • 3.3.1-1
    • 3.3.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird2 Ubuntu:26.04:LTS

    Versions
    • 2.17.1-1
    • 2.17.2-1
    • 2.17.3-1
    • 2.17.3-2
    • 2.18-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • bird3 Ubuntu:26.04:LTS

    Versions
    • 3.1.0-1
    • 3.1.4-1
    • 3.1.5-1
    • 3.1.5-2
    • 3.2.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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