How severe is CVE-2026-55957?

CVE-2026-55957 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-55957 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-55957?

CVE-2026-55957 affects Apache Tomcat. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-55957?

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.

When was CVE-2026-55957 published?

CVE-2026-55957 was published on 2026-06-29 and last updated on 2026-07-02.

CVE-2026-55957

CVE-2026-55957 is a high-severity vulnerability in Apache Tomcat with a CVSS 3.x base score of 7.3. 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-304.

Key facts

Severity: High (CVSS 3.x base score 7.3)
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-304
Affected product: Apache Tomcat
Published: 2026-06-29
Last modified: 2026-07-02

Description

Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

Frequently asked questions

What is CVE-2026-55957?: Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.
How severe is CVE-2026-55957?: CVE-2026-55957 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-55957 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-55957?: CVE-2026-55957 affects Apache Tomcat. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-55957?: 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.
When was CVE-2026-55957 published?: CVE-2026-55957 was published on 2026-06-29 and last updated on 2026-07-02.

References

Affected products (1)

cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*

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