CVE-2026-49943

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

Score 6.3 from GitHub Security Advisory published 2026-06-02. a secondary CVSS source baseline 6.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
6.3
EG Score
6.3(medium)
EG Risk
28(Track)
EG Risk 28/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity63% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

June 2, 2026

Last Modified

July 22, 2026

Advisory Details (2)

Auto-updated Jun 13, 2026
No patch confirmed yet.
generic

NEWS · master · labs / BIRD Internet Routing Daemon · GitLab

https://gitlab.nic.cz/labs/bird/-/blob/master/NEWS
generic

BIRD Internet Routing Daemon

https://bird.nic.cz

Vendor Advisories for CVE-2026-49943(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(8 across 4 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
bird1.6.8-2.1——
bird22.0.10-1 ... 2.19.2-1 (33 versions)——
Debian:12(2)
PackageVulnerable rangeFixed inDependents
bird1.6.8-2.1——
bird22.0.12-7 ... 2.19.2-1 (17 versions)——
Debian:13(2)
PackageVulnerable rangeFixed inDependents
bird22.17.1-1 ... 2.19.2-1 (12 versions)——
bird33.1.0-1 ... 3.3.2-1~bpo13+1 (12 versions)——
Debian:14(2)
PackageVulnerable rangeFixed inDependents
bird22.17.1-1 ... 2.19.2-1 (9 versions)——
bird33.1.0-1 ... 3.3.2-1~bpo13+1 (11 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 34× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 194 total refreshes for this CVE.

  1. 2026-09-16 05:15 UTCEPSS rescore
  2. 2026-09-14 05:45 UTCEG score recompute
  3. 2026-09-14 05:45 UTCGHSA enrichment
  4. 2026-09-13 16:47 UTCEPSS rescore
  5. 2026-09-13 00:06 UTCOSV refresh
  6. 2026-09-11 14:53 UTCEPSS rescore
  7. 2026-09-10 09:35 UTCEPSS rescore
  8. 2026-09-08 22:01 UTCEPSS rescore
  9. 2026-09-07 16:01 UTCEPSS rescore
  10. 2026-09-06 13:47 UTCEPSS rescore
  11. 2026-09-04 05:06 UTCEPSS rescore
  12. 2026-09-02 14:12 UTCEPSS rescore
  13. 2026-09-01 13:54 UTCEPSS rescore
  14. 2026-09-01 04:40 UTCEPSS rescore
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-25 03:44 UTCEG score recompute
  22. 2026-08-25 03:44 UTCGHSA enrichment
  23. 2026-08-23 13:41 UTCEG score recompute
  24. 2026-08-23 13:41 UTCGHSA enrichment
  25. 2026-08-23 00:19 UTCEPSS rescore
Show 75 more
  1. 2026-08-21 23:49 UTCEPSS rescore
  2. 2026-08-21 14:45 UTCEG score recompute
  3. 2026-08-21 14:45 UTCGHSA enrichment
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 10:10 UTCEG score recompute
  6. 2026-08-20 10:10 UTCGHSA enrichment
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-17 04:06 UTCEG score recompute
  11. 2026-08-17 04:06 UTCGHSA enrichment
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 02:19 UTCEG score recompute
  14. 2026-08-16 02:19 UTCGHSA enrichment
  15. 2026-08-16 02:14 UTCEPSS rescore
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-14 23:24 UTCGHSA enrichment
  18. 2026-08-13 23:17 UTCEG score recompute
  19. 2026-08-13 23:17 UTCGHSA enrichment
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-12 23:10 UTCEG score recompute
  22. 2026-08-12 23:10 UTCGHSA enrichment
  23. 2026-08-12 13:51 UTCEPSS rescore
  24. 2026-08-11 23:03 UTCEG score recompute
  25. 2026-08-11 23:03 UTCGHSA enrichment
  26. 2026-08-11 00:00 UTCEPSS rescore
  27. 2026-08-10 22:57 UTCGHSA enrichment
  28. 2026-08-09 21:03 UTCEG score recompute
  29. 2026-08-09 21:03 UTCGHSA enrichment
  30. 2026-08-09 13:46 UTCEPSS rescore
  31. 2026-08-08 20:57 UTCEG score recompute
  32. 2026-08-08 20:57 UTCGHSA enrichment
  33. 2026-08-08 16:37 UTCEPSS rescore
  34. 2026-08-07 20:50 UTCEG score recompute
  35. 2026-08-07 20:50 UTCGHSA enrichment
  36. 2026-08-06 20:43 UTCEG score recompute
  37. 2026-08-06 20:43 UTCGHSA enrichment
  38. 2026-08-06 13:47 UTCEPSS rescore
  39. 2026-08-05 20:36 UTCEG score recompute
  40. 2026-08-05 20:36 UTCGHSA enrichment
  41. 2026-08-05 19:17 UTCEPSS rescore
  42. 2026-08-04 19:52 UTCEG score recompute
  43. 2026-08-04 19:52 UTCGHSA enrichment
  44. 2026-08-04 15:10 UTCEPSS rescore
  45. 2026-08-04 10:39 UTCEPSS rescore
  46. 2026-08-03 15:45 UTCEG score recompute
  47. 2026-08-03 15:45 UTCGHSA enrichment
  48. 2026-08-03 10:36 UTCEPSS rescore
  49. 2026-08-02 13:23 UTCEG score recompute
  50. 2026-08-02 13:23 UTCGHSA enrichment
  51. 2026-08-02 02:27 UTCEPSS rescore
  52. 2026-08-01 13:16 UTCEG score recompute
  53. 2026-08-01 13:16 UTCGHSA enrichment
  54. 2026-08-01 04:16 UTCEPSS rescore
  55. 2026-07-31 05:37 UTCEG score recompute
  56. 2026-07-31 05:37 UTCGHSA enrichment
  57. 2026-07-30 16:28 UTCEPSS rescore
  58. 2026-07-30 01:30 UTCEPSS rescore
  59. 2026-07-29 10:46 UTCEG score recompute
  60. 2026-07-29 10:46 UTCGHSA enrichment
  61. 2026-07-28 15:37 UTCEPSS rescore
  62. 2026-07-28 03:38 UTCEG score recompute
  63. 2026-07-28 03:38 UTCGHSA enrichment
  64. 2026-07-26 22:53 UTCEG score recompute
  65. 2026-07-26 22:53 UTCGHSA enrichment
  66. 2026-07-26 14:54 UTCEPSS rescore
  67. 2026-07-25 14:18 UTCEPSS rescore
  68. 2026-07-24 14:18 UTCEPSS rescore
  69. 2026-07-23 14:18 UTCEPSS rescore
  70. 2026-07-23 03:18 UTCEG score recompute
  71. 2026-07-22 14:08 UTCEPSS rescore
  72. 2026-07-21 15:25 UTCEPSS rescore
  73. 2026-07-20 17:08 UTCEPSS rescore
  74. 2026-07-19 14:31 UTCEPSS rescore
  75. 2026-07-19 14:31 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-49943?
CVE-2026-49943 is a medium vulnerability published on June 2, 2026. CZ.NIC BIRD Internet Routing Daemon through 2.19.0 contains a stack-based buffer overflow in the BGP ASPATH mask matching implementation in nest/a-path.c. The aspathmatch() function uses a fixed-size stack array of 2048 + 1 pmpos entries, while parsepath() expands ASPATH segments from a received…
When was CVE-2026-49943 disclosed?
CVE-2026-49943 was first published in the National Vulnerability Database on June 2, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-49943 actively exploited?
CVE-2026-49943 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.4% of all scored CVEs.
What is the CVSS score of CVE-2026-49943?
CVE-2026-49943 has a CVSS v3 base score of 6.3 (NVD).
How do I remediate CVE-2026-49943?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-49943, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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