# CVE-2026-65905 — Apache Tomcat > As of 2026-08-26, CVE-2026-65905 is a CRITICAL-severity vulnerability in Apache Tomcat, CVSS v3.1 9.8, EPSS 0.5% (45.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-65905, 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-2026-65905? Authentication Bypass by Capture-replay vulnerability in Apache Tomcat's DIGEST authenticator. If, before windowSize requests have been made, a client makes a DIGEST authenticated request with a nonceCount on the upper boundary of the replay window then that request is replayable once only while the associated nonceCount remains within the replay window. 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 7.0.30 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-2026-65905 under weakness class [CWE-294](https://intel.threadlinqs.com/cwe/CWE-294). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 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:** 9.8 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **EPSS (FIRST):** 0.5% probability of exploitation in the next 30 days, higher than 45.0% of all scored CVEs - **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog - **Threadlinqs priority:** 6.7/10 — 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-2026-65905 being exploited? It currently carries a trending score of 35 in the Threadlinqs vulnerability feed. ## Affected products and versions - [Apache Software Foundation](https://intel.threadlinqs.com/vendors/apache-software-foundation): Apache Tomcat Affected software packages: - `maven:org.apache.tomcat:tomcat` — patched in 11.0.25 - `maven:org.apache.tomcat:tomcat` — patched in 10.1.58 - `maven:org.apache.tomcat:tomcat` — patched in 9.0.121 - `maven:org.apache.tomcat:tomcat` - `maven:org.apache.tomcat:tomcat` - `maven:org.apache.tomcat.embed:tomcat-embed-core` — patched in 11.0.25 - `maven:org.apache.tomcat.embed:tomcat-embed-core` — patched in 10.1.58 - `maven:org.apache.tomcat.embed:tomcat-embed-core` — patched in 9.0.121 - `maven:org.apache.tomcat.embed:tomcat-embed-core` - `maven:org.apache.tomcat.embed:tomcat-embed-core` - `maven:org.apache.tomcat:tomcat-catalina` — patched in 11.0.25 - `maven:org.apache.tomcat:tomcat-catalina` — patched in 10.1.58 ## How to fix CVE-2026-65905 Fixed versions are recorded for 9 packages: maven:org.apache.tomcat:tomcat 11.0.25, maven:org.apache.tomcat:tomcat 10.1.58, maven:org.apache.tomcat:tomcat 9.0.121, maven:org.apache.tomcat.embed:tomcat-embed-core 11.0.25, maven:org.apache.tomcat.embed:tomcat-embed-core 10.1.58, maven:org.apache.tomcat.embed:tomcat-embed-core 9.0.121, maven:org.apache.tomcat:tomcat-catalina 11.0.25, maven:org.apache.tomcat:tomcat-catalina 10.1.58, maven:org.apache.tomcat:tomcat-catalina 9.0.121. No vendor patch reference has been recorded for CVE-2026-65905 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-2026-65905 1 tracked threat in the Threadlinqs corpus references CVE-2026-65905, 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/9v114xlpgbzrrbzz5vf9f6r2q4wnxwwj) Canonical: https://intel.threadlinqs.com/cve/CVE-2026-65905 Full detection coverage and IOCs for threats exploiting CVE-2026-65905 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp