An issue was discovered in FRRouting FRR through 9.0.

published 2023-09-05 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-46387

cvss: 7.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits: 0; none known

An issue was discovered in FRRouting FRR through 9.0. bgp_nlri_parse_flowspec in bgpd/bgp_flowspec.c processes malformed requests with no attributes, leading to a NULL pointer dereference.

Patch / fix

distros 7 links 1

debian ubuntu red hat suse opensuse almalinux rocky linux

frr Debian 14, Debian 13, Debian 12 8.4.4-1

debian advisories DEBIAN-CVE-2023-41909

frr Ubuntu 22.04 LTS 8.1-1ubuntu1.6
frr Ubuntu Pro 20.04 LTS 7.2.1-1ubuntu0.2+esm1

ubuntu advisories UBUNTU-CVE-2023-41909

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

frr RHEL 8 7.5.1-22.el8
frr-selinux RHEL 8 7.5.1-22.el8
frr RHEL 9 8.5.3-4.el9
frr-selinux RHEL 9 8.5.3-4.el9

red hat advisories RHSA-2024:2981 RHSA-2024:2156

frr SLE Module for Server Applications 15 SP6, SLE Module for Server Applications 15 SP5, openSUSE Leap 15.6 +1 more 8.5.6-150500.4.30.1
frr SLES for SAP 15 SP3, SLES 15 SP3-LTSS, SLE Module for Server Applications 15 SP4 +6 more 7.4-150300.4.17.1
frr SLE Module for Server Applications 15 SP5, openSUSE Leap 15.5 8.4-150500.4.8.1

suse advisories SUSE-SU-2024:4090-1 SUSE-SU-2023:3762-1 SUSE-SU-2023:3709-1

frr openSUSE Tumbleweed 8.4-6.1

opensuse advisories openSUSE-SU-2024:13238-1

frr AlmaLinux 8 7.5.1-22.el8
frr-selinux AlmaLinux 8 7.5.1-22.el8
frr AlmaLinux 9 8.5.3-4.el9
frr-selinux AlmaLinux 9 8.5.3-4.el9

almalinux advisories ALSA-2024:2981 ALSA-2024:2156

frr Rocky Linux 8 7.5.1-22.el8

rocky linux advisories RLSA-2024:2981

github.com/FRRouting/frr#13222 commit

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-2023-41909 updated 2025-11-21 cvss 7.5

frr: NULL pointer dereference in bgp_nlri_parse_flowspec() in bgpd/bgp_flowspec.c

Red Hat Enterprise Linux AppStream (v. 8) frr 7.5.1-22.el8, frr-selinux 7.5.1-22.el8
fixed: vendor fix RHSA-2024:2981
Red Hat Enterprise Linux AppStream (v. 9) frr 8.5.3-4.el9, frr-selinux 8.5.3-4.el9
fixed: vendor fix RHSA-2024:2156

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

1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

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-476 NULL Pointer Dereference

References

github.com /FRRouting/frr/pull/13222/commits/cfd04dcb3e689754a72507d086ba3b9709fc5ed8
patch
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/LMJNX44SMJM25JZO7XWHDQCOB4SNJPIE/
vendor-advisory, mailing-list
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/JLG64IF3FU7V76K4TKCCXVNEE6P2VUDO/
vendor-advisory, mailing-list
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/WXR6PIVY4SWO7HDT4EY733H4X32SCPM4/
vendor-advisory, mailing-list
lists.debian.org /debian-lts-announce/2023/09/msg00020.html
mailing-list, third-party-advisory

Sources

CVE List CVE-2023-41909
NVD CVE-2023-41909

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