How severe is CVE-2023-38406?

CVE-2023-38406 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-38406 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-38406?

CVE-2023-38406 affects Frrouting. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-38406?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2023-38406 published?

CVE-2023-38406 was published on 2023-11-06 and last updated on 2026-06-17.

CVE-2023-38406

CVE-2023-38406 is a critical-severity vulnerability in Frrouting with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-755.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (57th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-755
Affected product: Frrouting
Published: 2023-11-06
Last modified: 2026-06-17

Description

bgpd/bgp_flowspec.c in FRRouting (FRR) before 8.4.3 mishandles an nlri length of zero, aka a "flowspec overflow."

Frequently asked questions

What is CVE-2023-38406?: bgpd/bgp_flowspec.c in FRRouting (FRR) before 8.4.3 mishandles an nlri length of zero, aka a "flowspec overflow."
How severe is CVE-2023-38406?: CVE-2023-38406 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-38406 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (57th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-38406?: CVE-2023-38406 affects Frrouting. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-38406?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2023-38406 published?: CVE-2023-38406 was published on 2023-11-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:frrouting:frrouting:*:*:*:*:*:*:*:*

More vulnerabilities in Frrouting

CVE-2023-41361 — Critical (CVSS 9.8): An issue was discovered in FRRouting FRR 9.0. bgpd/bgp_open.c does not check for an overly large length of the rcv…
CVE-2023-41360 — Critical (CVSS 9.1): An issue was discovered in FRRouting FRR through 9.0. bgpd/bgp_packet.c can read the initial byte of the ORF header in…
CVE-2023-41359 — Critical (CVSS 9.1): An issue was discovered in FRRouting FRR through 9.0. There is an out-of-bounds read in bgp_attr_aigp_valid in…
CVE-2022-37032 — Critical (CVSS 9.1): An out-of-bounds read in the BGP daemon of FRRouting FRR before 8.4 may lead to a segmentation fault and denial of…
CVE-2022-37035 — High (CVSS 8.1): An issue was discovered in bgpd in FRRouting (FRR) 8.3. In bgp_notify_send_with_data() and bgp_process_packet() in…
CVE-2022-26129 — High (CVSS 7.8): Buffer overflow vulnerabilities exist in FRRouting through 8.1.0 due to wrong checks on the subtlv length in the…

All CVEs affecting Frrouting →

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