How severe is CVE-2024-39321?

CVE-2024-39321 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2024-39321 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-39321?

CVE-2024-39321 primarily affects Traefik. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2024-39321?

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

Does CVE-2024-39321 have an EU (EUVD) identifier?

Yes. CVE-2024-39321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-2353.

When was CVE-2024-39321 published?

CVE-2024-39321 was published on 2024-07-05 and last updated on 2026-06-17.

CVE-2024-39321

CVE-2024-39321 is a high-severity vulnerability in Traefik with a CVSS 3.x base score of 7.5. 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-639.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-2353
Weakness: CWE-639
Affected product: Traefik
Published: 2024-07-05
Last modified: 2026-06-17

Description

Traefik is an HTTP reverse proxy and load balancer. Versions prior to 2.11.6, 3.0.4, and 3.1.0-rc3 have a vulnerability that allows bypassing IP allow-lists via HTTP/3 early data requests in QUIC 0-RTT handshakes sent with spoofed IP addresses. Versions 2.11.6, 3.0.4, and 3.1.0-rc3 contain a patch for this issue. No known workarounds are available.

Frequently asked questions

What is CVE-2024-39321?: Traefik is an HTTP reverse proxy and load balancer. Versions prior to 2.11.6, 3.0.4, and 3.1.0-rc3 have a vulnerability that allows bypassing IP allow-lists via HTTP/3 early data requests in QUIC 0-RTT handshakes sent with spoofed IP addresses. Versions 2.11.6, 3.0.4, and 3.1.0-rc3 contain a patch for this issue. No known workarounds are available.
How severe is CVE-2024-39321?: CVE-2024-39321 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2024-39321 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-39321?: CVE-2024-39321 primarily affects Traefik. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2024-39321?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2024-39321 have an EU (EUVD) identifier?: Yes. CVE-2024-39321 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-2353.
When was CVE-2024-39321 published?: CVE-2024-39321 was published on 2024-07-05 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.1.0:-:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.1.0:rc1:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.1.0:rc2:*:*:*:*:*:*

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