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Public proof of conceptFix available

CVE-2026-55957

A public proof of concept exists; no exploitation attested.

  • Published2026-06-29
  • Fixed in11.0.5 · 10.1.37 · 9.0.101
  • WeaknessCWE-304

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-06-2921:16CVE publishedNVD
  2. 2026-10-2319:23First public proof of conceptPoC-in-GitHub

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-55957?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-55957?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Apache Tomcat
BranchAffectedFixed in
11.0≥ 11.0.0, < 11.0.511.0.5
10.1≥ 10.1.0, < 10.1.3710.1.37
9.0< 9.0.1019.0.101

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • RHSA-2026:68677 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: tomcat security update

  • RHSA-2026:68659 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: tomcat security update

  • RHSA-2026:68678 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: tomcat security update

  • RHSA-2026:68679 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: tomcat security update

  • RHSA-2026:68680 Red Hat Product Security18 products fixed

    Red Hat Security Advisory: tomcat security update

  • RHSA-2026:67163 Red Hat Product Security9 products fixed

    Red Hat Security Advisory: tomcat9 security update

1 more advisory

Full record on NVD

Fix

  1. Update Apache Tomcat to 11.0.5 · 10.1.37 · 9.0.101
  2. Vendor fix Red Hat Product Security RHSA-2026:68677 · 9 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. Workaround from the vendor Red Hat Product Security RHSA-2026:68677 · 9 productsRed Hat has investigated whether a possible mitigation exists for this issue, and has not been able to identify a practical example. Please update the affected package as soon as possible.

Advisories and patches

Detection

read 2026-10-23 19:25 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedmdvpat/CVE-2026-55957-PoC
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2026-06-29
Last Modified
2026-07-02
NVD status
Analyzed

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.

Is CVE-2026-55957 actively exploited?

Active exploitation of CVE-2026-55957 has not been confirmed. Its EPSS score was 2.9% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-55957?

CVE-2026-55957 has a CVSS v3 base score of 7.3 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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