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CVE-2026-42498

📛 CVE Title

Apache Tomcat: WebSocket authentication header exposure

⬇ Download JSON ⚠ View as Threat

Description

Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.

Overview

State
PUBLISHED
Assigner (CNA)
apache
CVSS severity
high
CVSS score
CVSS 7.3 / 10 7.3 7.3 / 10
CVSS vector
AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Effective score
7.3 / 10 HIGH source: CNA overview
CWE(s)
CWE-200
Reserved
2026-04-28
Published
2026-05-12 17:17 UTC
Last updated
2026-05-13 17:59 UTC
Source
https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/42xxx/CVE-2026-42498.json
Linked Threat
CVE-2026-42498 — CVE-2026-42498

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published
2026-05-12 16:16:17 UTC
NVD last modified
2026-05-14 18:51:59 UTC
NVD CVSS v3.1
CVSS 7.3 / 10 7.3 7.3 / 10 HIGH source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Exploitability subscore
3.9 / 10
Impact subscore
3.4 / 10
EPSS score
0.0005 (probability of exploitation in next 30 days)
EPSS percentile
15.62% vs all CVEs — higher = more likely to be exploited, as of 2026-05-24

NVD / KEV / EPSS data refreshed 2026-05-25 09:24 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID
EUVD-2026-29515
Assigner
apache
Published
May 12, 2026, 3:17:56 PM
Updated
May 13, 2026, 3:59:04 PM
EUVD base score (CVSS 3.1)
7.3 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EUVD-reported EPSS
0.0500
Vendors
Apache Software Foundation
Products
Apache Tomcat (11.0.0-M1 ≤11.0.21)
Apache Tomcat (10.1.0-M1 ≤10.1.54)
Apache Tomcat (9.0.2 ≤9.0.117)
Apache Tomcat (8.5.24 ≤8.5.100)
Apache Tomcat (7.0.83 ≤7.0.109)

ENISA description: Exposure of HTTP Authentication Header to unexpected hosts during WebSocket authentication vulnerability in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.2 through 9.0.117, from 8.5.24 through 8.5.100, from 7.0.83 through 7.0.109. Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118, which fix the issue.

EUVD references (1)

Affected products (1)
VendorProductVersionsPlatforms
Apache Software Foundation Apache Tomcat 11.0.0-M1 (affected), 10.1.0-M1 (affected), 9.0.2 (affected), 8.5.24 (affected), 7.0.83 (affected) —

Affected products — CPE 2.3 (1) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

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

Vendor references (1)

References embedded in the original CVE record by the assigning CNA.

MITRE references (1) cveawg.mitre.org

Pulled from MITRE's CVE Services API by the 🛰 Backfill from MITRE button.

Web references (10)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

NVD-tagged references (2)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

Remediations (14)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

  • Microsoft Defender CVE-2026-41091 and CVE-2026-45498 Exploited
    web:blog.gridinsoft.com

    Microsoft has confirmed exploitation of two Microsoft Defender vulnerabilities fixed in the May 2026 security update cycle. CVE - 2026 -41091 is an elevation-of-privilege flaw in the Microsoft Malware Protection Engine, while CVE - 2026 -45498 is a denial-of-service flaw in the Microsoft Defender Antimalware Platform . The first bug matters more for incident response because a local authorized ...

    2026-05-23 20:58 UTC
  • CISA Warns of Exploited Microsoft Defender 0-Day Flaws
    web:cyberpress.org

    The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two actively exploited Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, issuing an urgent remediation directive for federal agencies with a due date of June 3, 2026 .

    2026-05-23 20:58 UTC
  • CISA Warns of Microsoft Defender 0-Day Vulnerabilities Exploited in Attacks
    web:cybersecuritynews.com

    The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added two critical Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog, warning organizations of active exploitation risks. The flaws, tracked as CVE - 2026 -45498 and CVE - 2026 -41091, impact Microsoft Defender and could allow attackers to disrupt systems or escalate privileges. Both ...

    2026-05-23 20:58 UTC
  • Microsoft Defender CVE-2026-41091 and CVE-2026-45498 Exploited
    web:howtofix.guide

    CISA added both CVE - 2026 -41091 and CVE - 2026 -45498 to its Known Exploited Vulnerabilities catalog on May 20, with a federal remediation due date of June 3, 2026 . [4] That KEV entry does not mean every home PC is currently targeted, but it is a clear signal that defenders should not wait for the next normal maintenance window.

    2026-05-23 20:58 UTC
  • Nvd - Cve-2026-42498
    web:nvd.nist.gov

    Official websites use .gov A .gov website belongs to an official government organization in the United States.

    2026-05-23 20:58 UTC
  • Security Update Guide - Microsoft
    web:portal.msrc.microsoft.com

    The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

    2026-05-23 20:58 UTC
  • Microsoft Defender CVE-2026-41091 & CVE-2026-45498
    web:thecyberexpress.com

    Microsoft confirms active exploitation of CVE - 2026 -41091 and CVE - 2026 -45498 in Defender, with CVSS-rated risks, KEV listing, and urgent patches issued.

    2026-05-23 20:58 UTC
  • Microsoft Warns of Two Actively Exploited Defender Vulnerabilities
    web:thehackernews.com

    Active Defender exploits hit CVE - 2026 -41091 and CVE - 2026 -45498; June 3 fixes reduce SYSTEM and DoS risk.

    2026-05-23 20:58 UTC
  • 2 New Microsoft Defender Zero-Days Exploited—Patch Now ... - Forbes
    web:www.forbes.com

    Microsoft has confirmed an emergency security update as CISA warns that two new Defender zero-days are being exploited by attackers.

    2026-05-23 20:58 UTC
  • Windows 11's Secure Boot fix update finally rolls out to ... - PCWorld
    web:www.pcworld.com

    Windows 11's Secure Boot fix update finally rolls out to more PCs Important security certificates for Windows 11 will soon expire for many users.

    2026-05-23 20:58 UTC
  • Microsoft Defender Flaws CVE-2026-41091 And -45498
    web:cybersecurefox.com

    Given the confirmed active exploitation and the CISA deadline of June 3, 2026 , remediation of CVE - 2026 -41091 should be treated as critical —immediate verification and updating of all systems with active Microsoft Defender, with special attention to servers and workstations that have access to sensitive data or privileged accounts.

    2026-05-26 02:53 UTC
  • Microsoft Defender Vulnerabilities Added to CISA KEV (CVE-2026-41091 ...
    web:op-c.net

    CISA has added two Microsoft Defender vulnerabilities to its Known Exploited Vulnerabilities catalog following evidence of active exploitation. The vulnerabilities, tracked as CVE - 2026 -41091 and CVE - 2026 -45498, affect core Microsoft Defender components used to protect Windows endpoints. CISA added both vulnerabilities to KEV on May 20, 2026 , with a federal remediation due date of June 3, 2026 .

    2026-05-26 02:53 UTC
  • Microsoft Technical Security Notifications
    web:www.microsoft.com

    Security Update Guide Notifications Microsoft's free Security Update Guide Notifications provide links to security-related software updates and notification of re-released security updates. These notifications are sent via email throughout the month as needed.

    2026-05-26 02:53 UTC
  • Microsoft confirms two major Defender security issues - TechRadar
    web:www.techradar.com

    Microsoft patches two actively exploited zero‑day flaws in Defender, tracked as CVE‑2026‑41091 (privilege escalation) and CVE‑2026‑45498 (denial of service) Updates were shipped ...

    2026-05-26 02:53 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2026-42498.json.

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