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TI-2026-36792 Aliases CVE-2026-49943GHSA-64c8-8qx9-25r7

Stack-based buffer overflow in CZ.NIC BIRD

Priority LOW 28CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-121 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.003 22nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
CZ.NICBIRDup to 2.19.0—No fix listedCNA
  • BIRD VendorCZ.NIC Affected up to 2.19.0 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-49943
  2. 2026-10-03 Alias added: GHSA-64c8-8qx9-25r7

References

Other 2

  • TI-2023-27571 Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related… CVSS 3.1HIGH 7.5
  • TI-2026-47140 Knot Resolver before 6.4.1 allows remote code execution via a heap-based buffer overflow… CVSS 3.1HIGH 8.1
  • TI-2021-08533 BIRD through 2.0.7 does not provide functionality for password authentication of BGP… CVSS 3.1MEDIUM 6.8
  • TI-2021-02344 Foris before 101.1.1, as used in Turris OS, lacks certain HTML escaping in the login template. CVSS 3.1CRITICAL 9.8
  • TI-2020-10072 Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an… CVSS 3.1HIGH 7.5
  • TI-2022-19055 Knot Resolver before 5.5.3 allows remote attackers to cause a denial of service (CPU… CVSS 3.1HIGH 7.5
See all 20 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences