How severe is CVE-2026-35051?

CVE-2026-35051 has a CVSS 3.x base score of 10.0, 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 none.

Is CVE-2026-35051 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35051?

CVE-2026-35051 primarily affects Traefik. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-35051?

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.

Does CVE-2026-35051 have an EU (EUVD) identifier?

Yes. CVE-2026-35051 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26426.

When was CVE-2026-35051 published?

CVE-2026-35051 was published on 2026-04-30 and last updated on 2026-06-30.

CVE-2026-35051

CVE-2026-35051 is a critical-severity vulnerability in Traefik with a CVSS 3.x base score of 10.0. 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-345.

Key facts

Severity: Critical (CVSS 3.x base score 10.0)
CVSS v4: 7.8
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-26426
Weakness: CWE-345
Affected product: Traefik
Published: 2026-04-30
Last modified: 2026-06-30

Description

Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is an authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.

Frequently asked questions

What is CVE-2026-35051?: Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is an authentication bypass vulnerability in Traefik's ForwardAuth middleware when trustForwardHeader=false is configured and Traefik is deployed behind a trusted upstream proxy. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2.
How severe is CVE-2026-35051?: CVE-2026-35051 has a CVSS 3.x base score of 10.0, 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 none.
Is CVE-2026-35051 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35051?: CVE-2026-35051 primarily affects Traefik. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-35051?: 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.
Does CVE-2026-35051 have an EU (EUVD) identifier?: Yes. CVE-2026-35051 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-26426.
When was CVE-2026-35051 published?: CVE-2026-35051 was published on 2026-04-30 and last updated on 2026-06-30.

References

Affected products (5)

cpe:2.3:a:traefik:traefik:*:*:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.7.0:ea1:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.7.0:ea2:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.7.0:ea3:*:*:*:*:*:*
cpe:2.3:a:traefik:traefik:3.7.0:rc1:*:*:*:*:*:*

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