[UPDATE] [medium] Apache Tomcat: Multiple vulnerabilities
An attacker can exploit multiple vulnerabilities in Apache Tomcat to bypass security measures, cause a Denial-of-Service condition, conduct Cross-Site Scripting attacks, or trigger other unspecified impacts.
CSIRTS triage
- What
- An attacker can exploit multiple vulnerabilities in Apache Tomcat to bypass security measures, cause a Denial-of-Service condition, conduct Cross-Site Scripting attacks, or trigger other unspecified impacts.
- Who is affected
- Deployments of Apache Tomcat are affected.
- Urgency
- Remediation is medium urgency due to the potential for various impacts including Denial of Service.
- Action
- Apply the latest security updates for Apache Tomcat.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2123
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Moderate exploitation riskCVE-2026-502294.2% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 90% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-534040.58% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 45% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-534340.53% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 42% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-552760.54% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 43% of all EPSS-scored CVEs.
- Low exploitation riskCVE-2026-559550.47% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.
- Moderate exploitation riskCVE-2026-559561.5% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 72% of all EPSS-scored CVEs.
- Moderate exploitation riskCVE-2026-559572.9% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 86% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-50229 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53404 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-53434 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-55276 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-55955 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-55956 | coverage & exploitation status | NVD · CVE.org |
| CVE-2026-55957 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownNCSC-2026-0309 [1.00] [M/H] Vulnerabilities resolved in Oracle Communicationsncsc-nl
- high[NEW] [HIGH] Oracle Communications: Multiple Vulnerabilitiescert-bund
- unknownUSN-8551-1: Tomcat vulnerabilitiesubuntu
- unknownApache Tomcat Multiple Vulnerabilitieshkcert
- unknownMultiple vulnerabilities in Apache Tomcat (June 30, 2026)cert-fr-avis
- highCVE-2026-55957: Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was …nvd
- mediumCVE-2026-55956: Improper Authorization vulnerability in Apache Tomcat leads to security constraints specified …nvd
- mediumCVE-2026-55955: Improper Authentication vulnerability in Apache Tomcat allowed a replay attack against the Enc…nvd
- criticalCVE-2026-55276: Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat meant that special…nvd
- criticalCVE-2026-53434: Detection of Error Condition Without Action vulnerability in Apache Tomcat when configuring CR…nvd
- highCVE-2026-53404: Always-Incorrect Control Flow Implementation vulnerability in Apache Tomcat's rewrite valve me…nvd
- mediumCVE-2026-50229: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) vulnerability in…nvd
Recent advisories for Apache Tomcat
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- unknownCVE-2026-73180: Insufficient Session Expiration vulnerability in Apache Tomcat meant that if the session ID fo…nvd · 2026-08-25
- unknownCVE-2026-68763: Uncontrolled Resource Consumption vulnerability in Apache Tomcat via an allocation leak in the…nvd · 2026-08-25
- unknownCVE-2026-68569: Improper Authentication vulnerability in Apache Tomcat meant that in some circumstances (e.g. …nvd · 2026-08-25
- unknownCVE-2026-68525: Incorrect Authorization vulnerability in Apache Tomcat's FORM authentication process allows th…nvd · 2026-08-25
- unknownCVE-2026-66422: Improper Authorization vulnerability in Apache Tomcat cause by security-role-ref definitions b…nvd · 2026-08-25
- unknownCVE-2026-65927: Off-by-one Error vulnerability in Apache Tomcat impacting the [N] flag on the rewrite valves c…nvd · 2026-08-25
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