Affects widely used Apache Tomcat across multiple versions; critical risk of unauthorized access.
CVE-2026-43515
Tomcat: improper authorization via conflicting HTTP method constraints.
Is CVE-2026-43515 being exploited?
Not confirmed. CVE-2026-43515 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.2% probability of exploitation in the next 30 days.
How severe is CVE-2026-43515?
CVE-2026-43515 is rated Critical with a CVSS score of 9.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-43515?
Yes. A fix has been recorded for CVE-2026-43515. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43515 affect?
CVE-2026-43515 affects Apache Tomcat 7.0.0 - 7.0.109, Apache Tomcat 8.5.0 - 8.5.100, Apache Tomcat 9.0.0.M1 - 9.0.117, Apache Tomcat 10.1.0-M1 - 10.1.54, and 1 further product or version. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43515?
Upgrade to fixed versions: 11.0.22, 10.1.55 or 9.0.118
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Bypass of resource access controls via HTTP method constraint confusion; unauthorized data access/modification.
Immediate action required
- affected>= 11.0.0-M1 and <= 11.0.21
- affected>= 10.1.0-M1 and <= 10.1.54
- affected>= 9.0.0.M1 and <= 9.0.117
- affected>= 8.5.0 and <= 8.5.100
- affected>= 7.0.0 and <= 7.0.109
- affected< 7.0.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.