Apache Tomcat Native Updates Address Three TLS Flaws
Tech GuruQuick Answer
The authority published CVE-2026-86243 for Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8. Buffer over-read vulnerability in Apache Tomcat Native during the TLS handshake permits a malicious user to trigger a DoS via a JVM crash. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Earlier, unsupported versions may also be affected. Initialization of a resource with an insecure default vulnerability in Apache Tomcat Native enabled insecure options by default including ALLOW_CLIENT_RENEGOTIATION, NO_EXTENDED_MASTER_SECRET, IGNORE_UNEXPECTED_EOF and ALLOW_NO_DHE_KEX. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Earlier unsupported versions may also be affected. Race condition within a thread vulnerability in Apache Tomcat Native allowed client certificate verification requirements to be down-graded for some configurations. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Unsupported versions may also be affected. Affected deployments should be matched to the authority's exact scope and moved to the supported fixed release.
Confirm Scope And Apply The Supported Fix
What to do now: Inventory Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8, match the exact affected release or feature, apply the authority-supported fixed build or service remediation, validate the dependent workflow, and preserve evidence.
Last verified: 2026-09-23 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 |
|---|---|
| Advisory | CVE-2026-86243 / CVE-2026-86246 / CVE-2026-86247 |
| CVEs | CVE-2026-86243, CVE-2026-86246, CVE-2026-86247 |
| Authoritative release date | 2026-09-23 12:24:55.119 UTC |
| Authority revision date | 2026-09-23 15:30:52.270 UTC |
| Affected versions | Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 |
| Fixed version | Apache Tomcat Native 2.0.16 or 1.3.9 |
| CVSS base score | Not provided by the authority |
| CVSS severity | Moderate to Important |
| Exploitation status | Not stated by the authority; no exploitation claim is inferred. |
What Changed
Buffer over-read vulnerability in Apache Tomcat Native during the TLS handshake permits a malicious user to trigger a DoS via a JVM crash. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Earlier, unsupported versions may also be affected. Initialization of a resource with an insecure default vulnerability in Apache Tomcat Native enabled insecure options by default including ALLOW_CLIENT_RENEGOTIATION, NO_EXTENDED_MASTER_SECRET, IGNORE_UNEXPECTED_EOF and ALLOW_NO_DHE_KEX. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Earlier unsupported versions may also be affected. Race condition within a thread vulnerability in Apache Tomcat Native allowed client certificate verification requirements to be down-graded for some configurations. This issue affects Apache Tomcat Native: from 2.0.0 through 2.0.15, from 1.3.0 through 1.3.8. Unsupported versions may also be affected.
What To Validate Now
- Inventory. Locate Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 deployments, versions, enabled features, exposure paths, owners, and dependent services.
- Establish applicability. Compare each deployment with the authority's affected-version statement: Apache Tomcat Native 2.0.0 through 2.0.15 and 1.3.0 through 1.3.8 Do not infer applicability from product family or severity alone.
- Remediate. Apply Apache Tomcat Native 2.0.16 or 1.3.9 through the supported vendor or project channel, following the current advisory and change-control requirements.
- Validate. Confirm the resulting version or managed-service state, exercise representative functionality and recovery paths, monitor for regressions, and document exceptions.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
