CVE-2026-55955

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-06-29. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 5 sources updated this week
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component.

This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109.

Users are recommended to upgrade to version 11.0.23, 10.1.56, 9.0.119, which fixes the issue.

CVSS v3
6.5
EG Score
6.5(high)
EPSS
19.8%
KEV
Not listed

Published

June 29, 2026

Last Modified

July 2, 2026

Advisory Details (2)

Auto-updated Jun 30, 2026
No patch confirmed yet.
generic

oss-security - CVE-2026-55955: Apache Tomcat: EncryptInterceptor not protected against replay attacks

http://www.openwall.com/lists/oss-security/2026/06/29/24
generic
https://lists.apache.org/thread/g4p5sf45p3f9r011pwqs9r54yd64s106

Vendor Advisories for CVE-2026-55955(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhattomcat11-main-11.0.23-0.1.hum12026-06-29redhat
redhattomcat10-main-10.1.56-1.hum12026-06-24redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 26× in last 7d / 31× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-06 23:26 UTCEG score recompute
  2. 2026-07-06 23:26 UTCVendor advisory
  3. 2026-07-06 23:26 UTCGHSA enrichment
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 16:27 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 02:23 UTCEPSS rescore
  8. 2026-07-05 21:41 UTCEG score recompute
  9. 2026-07-05 21:41 UTCVendor advisory
  10. 2026-07-05 21:41 UTCGHSA enrichment
  11. 2026-07-05 02:31 UTCEPSS rescore
  12. 2026-07-05 02:30 UTCEPSS rescore
  13. 2026-07-04 19:56 UTCEG score recompute
  14. 2026-07-04 19:56 UTCVendor advisory
  15. 2026-07-04 19:56 UTCGHSA enrichment
  16. 2026-07-04 06:31 UTCEPSS rescore
  17. 2026-07-04 06:31 UTCEPSS rescore
  18. 2026-07-03 18:11 UTCEG score recompute
  19. 2026-07-03 18:11 UTCVendor advisory
  20. 2026-07-03 18:11 UTCGHSA enrichment
  21. 2026-07-02 16:27 UTCEG score recompute▲ 6.50
  22. 2026-07-02 16:27 UTCVendor advisory
  23. 2026-07-02 16:27 UTCGHSA enrichment
  24. 2026-07-01 15:07 UTCEPSS rescore
  25. 2026-06-30 23:22 UTCEPSS rescore
Show 6 more
  1. 2026-06-30 14:32 UTCNVD updateCVSS v3 → 6.5 · severity → MEDIUM
  2. 2026-06-30 00:21 UTCNVD update
  3. 2026-06-29 22:44 UTCMITRE cvelistV5
  4. 2026-06-29 21:26 UTCNVD update
  5. 2026-06-29 20:57 UTCEG score recompute
  6. 2026-06-29 20:57 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55955?
CVE-2026-55955 is a medium vulnerability published on June 29, 2026. Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the EncryptionInterceptor in the cluster component. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.22, from 10.1.0-M1 through 10.1.55, from 9.0.13 through 9.0.18, from 8.5.38 through 8.5.100, from…
When was CVE-2026-55955 disclosed?
CVE-2026-55955 was first published in the National Vulnerability Database on June 29, 2026, with the most recent update on July 2, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55955 actively exploited?
CVE-2026-55955 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 19.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55955?
CVE-2026-55955 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-55955?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55955, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-55955

Explore →

Is Your Infrastructure Affected by CVE-2026-55955?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs