# CVE-2026-73180 — Apache Tomcat

> As of 2026-08-26, CVE-2026-73180 is a MEDIUM-severity vulnerability in Apache Tomcat, CVSS v3.1 6.8, EPSS 0.4% (36.3th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-73180, most recently “Apache Tomcat 11.0.25 Fixes 11 Vulnerabilities Including HTTP/2 DoS, Authorization Bypass, and Auth Fail-Open Flaws — NVD Scores 5 of 11 CRITICAL/HIGH Despite Apache's Low/Moderate Ratings”.

**Last updated:** 2026-08-26

## What is CVE-2026-73180?

Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID for an authenticated HTTP session was changed after a WebSocket connection had been established under that authenticated HTTP session, the WebSokcet session would not be closed as required by the Jakarta WebSocket specification when the HTTP session ended. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.0.M1 through 9.0.120. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100, from 7.0.43 through 7.0.109. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.

The record classifies CVE-2026-73180 under weakness class [CWE-613](https://intel.threadlinqs.com/cwe/CWE-613). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 61 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 6.8 — MEDIUM (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 36.3% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.9/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-25, last modified 2026-08-26

## Is CVE-2026-73180 being exploited?

It currently carries a trending score of 33 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Apache Software Foundation](https://intel.threadlinqs.com/vendors/apache-software-foundation): Apache Tomcat

## How to fix CVE-2026-73180

No vendor patch reference has been recorded for CVE-2026-73180 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-73180

1 tracked threat in the Threadlinqs corpus references CVE-2026-73180, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Apache Tomcat 11.0.25 Fixes 11 Vulnerabilities Including HTTP/2 DoS, Authorization Bypass, and Auth Fail-Open Flaws — NVD Scores 5 of 11 CRITICAL/HIGH Despite Apache's Low/Moderate Ratings](https://intel.threadlinqs.com/threat/TL-2026-2159) — CRITICAL · 2026-08-26

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Vendor advisory and patch**

- [lists.apache.org — vendor advisory](https://lists.apache.org/thread/3j15vztszpyqss253mjq5v1kp7s6hooq)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-73180
Full detection coverage and IOCs for threats exploiting CVE-2026-73180 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp