Unrated

DEBIAN-CVE-2026-49943

Type: advisorySource: OSV1 source record

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.

Announced 2 Jun 2026Source revision 1

Original source ↗

DEBIAN-CVE-2026-49943

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-49943

bird

Source reference: /affected/0/package/name

Affected versions: 1.6.8-2.1
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

bird2

Source reference: /affected/1/package/name

Affected versions: 2.0.12-7
Source reference: /affected/1/versions
2.14-1
Source reference: /affected/1/versions
2.15-1
Source reference: /affected/1/versions
2.15.1-1
Source reference: /affected/1/versions
2.15.1-1.1
Source reference: /affected/1/versions
2.16-1
Source reference: /affected/1/versions
2.16.1-1
Source reference: /affected/1/versions
2.17-1
Source reference: /affected/1/versions
2.17.1-1
Source reference: /affected/1/versions
2.17.2-1
Source reference: /affected/1/versions
2.17.3-1
Source reference: /affected/1/versions
2.17.3-2
Source reference: /affected/1/versions
2.18-1
Source reference: /affected/1/versions
2.18.1-1
Source reference: /affected/1/versions
2.19.0-1
Source reference: /affected/1/versions
2.19.1-1
Source reference: /affected/1/versions
2.19.2-1
Source reference: /affected/1/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

bird2

Source reference: /affected/2/package/name

Affected versions: 2.17.1-1
Source reference: /affected/2/versions
2.17.1-1+deb13u1
Source reference: /affected/2/versions
2.17.1-1+deb13u2
Source reference: /affected/2/versions
2.17.2-1
Source reference: /affected/2/versions
2.17.3-1
Source reference: /affected/2/versions
2.17.3-2
Source reference: /affected/2/versions
2.17.5-0+deb13u1
Source reference: /affected/2/versions
2.18-1
Source reference: /affected/2/versions
2.18.1-1
Source reference: /affected/2/versions
2.19.0-1
Source reference: /affected/2/versions
2.19.1-1
Source reference: /affected/2/versions
2.19.2-1
Source reference: /affected/2/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

bird2

Source reference: /affected/3/package/name

Affected versions: 2.17.1-1
Source reference: /affected/3/versions
2.17.2-1
Source reference: /affected/3/versions
2.17.3-1
Source reference: /affected/3/versions
2.17.3-2
Source reference: /affected/3/versions
2.18-1
Source reference: /affected/3/versions
2.18.1-1
Source reference: /affected/3/versions
2.19.0-1
Source reference: /affected/3/versions
2.19.1-1
Source reference: /affected/3/versions
2.19.2-1
Source reference: /affected/3/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

bird3

Source reference: /affected/4/package/name

Affected versions: 3.1.0-1
Source reference: /affected/4/versions
3.1.4-1
Source reference: /affected/4/versions
3.1.5-1
Source reference: /affected/4/versions
3.1.5-2
Source reference: /affected/4/versions
3.1.7-0+deb13u1
Source reference: /affected/4/versions
3.2.0-1
Source reference: /affected/4/versions
3.2.1-1
Source reference: /affected/4/versions
3.3.0-1
Source reference: /affected/4/versions
3.3.0-1~bpo13+1
Source reference: /affected/4/versions
3.3.1-1
Source reference: /affected/4/versions
3.3.2-1
Source reference: /affected/4/versions
3.3.2-1~bpo13+1
Source reference: /affected/4/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

bird3

Source reference: /affected/5/package/name

Affected versions: 3.1.0-1
Source reference: /affected/5/versions
3.1.4-1
Source reference: /affected/5/versions
3.1.5-1
Source reference: /affected/5/versions
3.1.5-2
Source reference: /affected/5/versions
3.2.0-1
Source reference: /affected/5/versions
3.2.1-1
Source reference: /affected/5/versions
3.3.0-1
Source reference: /affected/5/versions
3.3.0-1~bpo13+1
Source reference: /affected/5/versions
3.3.1-1
Source reference: /affected/5/versions
3.3.2-1
Source reference: /affected/5/versions
3.3.2-1~bpo13+1
Source reference: /affected/5/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

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      "ecosystem": "Debian:12"
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    "versions": [
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      "3.2.0-1",
      "3.2.1-1",
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    "ranges": [
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      "name": "bird3",
      "purl": "pkg:deb/debian/bird3?arch=source&distro=forky",
      "ecosystem": "Debian:14"
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    "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",
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      "3.3.1-1",
      "3.3.2-1",
      "3.3.2-1~bpo13+1"
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    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49943.json"
    },
    "ecosystem_specific": {
      "urgency": "unimportant"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #56055 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 16:20:19 GMT
Publisher date: Tue, 02 Jun 2026 17:16:37 GMT

Read the original announcement