A reachable assertion was found in Frrouting frr-bgpd 8.3.0 in the peek_for_as4_capability function.

published 2023-04-03 3 y ago modified 2026-06-17 4 mo ago also EUVD-2022-39150

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.6%; EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits: 0; none known

A reachable assertion was found in Frrouting frr-bgpd 8.3.0 in the peek_for_as4_capability function. Attackers can maliciously construct BGP open packets and send them to BGP peers running frr-bgpd, resulting in DoS.

Patch / fix

distros 3

debian red hat almalinux

frr Debian 14, Debian 13, Debian 12 8.4.1-1

debian advisories DEBIAN-CVE-2022-36440

frr RHEL 9 8.3.1-11.el9_3
frr-selinux RHEL 9 8.3.1-11.el9_3

red hat advisories RHSA-2023:6434

frr AlmaLinux 9 8.3.1-11.el9_3.alma.1
frr-selinux AlmaLinux 9 8.3.1-11.el9_3.alma.1

almalinux advisories ALSA-2023:6434

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-36440 updated 2026-11-05 cvss 7.5

frr: Reachable assertion in peek_for_as4_capability function

Red Hat Enterprise Linux AppStream (v. 9) frr 8.3.1-11.el9_3, frr-selinux 8.3.1-11.el9_3
fixed: vendor fix RHSA-2023:6434
Red Hat Enterprise Linux 8 frr, frr-contrib, frr-selinux
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.62% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/spwpun/pocs/blob/main/frr-bgpd.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Classification

Weakness

CWE-617 Reachable Assertion

References

github.com /spwpun/pocs/blob/main/frr-bgpd.md
exploit, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/GM66PNHGCXZU66LQCTP2FSJLFF6CVMSI/
vendor-advisory, mailing-list, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/3HU4PKLUVB5CTMOVQ2GV33TNUNMJCBGD/
vendor-advisory, mailing-list, third-party-advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/BBXEXL2ZQBWCBLNUP6P67FHECXQWSK3L/
vendor-advisory, mailing-list, third-party-advisory
debian.org /security/2023/dsa-5495
vendor-advisory, third-party-advisory
github.com /spwpun/pocs
third-party-advisory
lists.debian.org /debian-lts-announce/2023/09/msg00020.html
mailing-list, third-party-advisory

Sources

CVE List CVE-2022-36440
NVD CVE-2022-36440

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary