Critical

Improper Authorization in Apache Tomcat security constraint method handling

IdentifiersCVE-2026-43515CWE-863

Apache Tomcat contains an improper authorization flaw in its handling of security constraints when multiple method constraints define an HTTP method for the same extension pattern. In affected releases, only the first matching method constraint is applied, causing subsequent constraints for the same extension pattern to be ignored. This can result in incorrect enforcement of configured HTTP method restrictions and security constraints for protected resources. Affected versions are Apache Tomcat 11.0.0-M1 through 11.0.21, 10.1.0-M1 through 10.1.54, 9.0.0.M1 through 9.0.117, 8.5.0 through 8.5.100, and 7.0.0 through 7.0.109.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can cause intended access-control and HTTP method restrictions to be bypassed for requests matching the affected extension patterns. This weakens authorization enforcement and may permit unauthorized use of methods that administrators expected to be restricted, potentially enabling authentication bypass in some deployments, exposure of protected functionality, or access to sensitive application behavior depending on the application’s security-constraint configuration.

Mitigation

If you can’t patch tonight, do this now.

If immediate patching is not possible, review and minimize reliance on overlapping or multiple method constraints for the same extension pattern, and validate that authorization rules for protected resources are enforced as intended. Restrict exposure of affected applications, place additional access controls in front of Tomcat where feasible, and test security-constraint behavior for all relevant HTTP methods until an upgrade can be completed. No complete workaround is documented in the available information; upgrading is the primary mitigation.

Remediation

Patch, then assume compromise.

Upgrade Apache Tomcat to a fixed release. The vendor-recommended fixed versions are 11.0.22 or later, 10.1.55 or later, and 9.0.118 or later. For deployments on older branches such as 8.5.x and 7.0.x, migrate to a supported fixed branch because those versions are listed as affected and no fixed release for those unsupported branches is provided in the available information.

PUBLIC EXPLOITS

Exploits

No valid public exploits. Mallory filtered out 2 candidates as fakes, detection scripts, or README-only repos.

VALID 0 / 2 TOTALView more in app

All candidate exploits were filtered out by Mallory's validation.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

Apache Software FoundationTomcatapplication

Apache Software FoundationTomcat-Catalinaapplication

Apache Software FoundationTomcat-Embed-Coreapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

14 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

14 SOURCESView more in app

cyber security newsNews

Jul 14, 2026

SAP Security Update July 2026 - Patch for Critical SAP NetWeaver Flaw that Enables Memory Corruption

One of multiple Apache Tomcat vulnerabilities affecting SAP Commerce Cloud.

cryptika blogNews

Jul 14, 2026

SAP Security Update July 2026 - Patch for Critical SAP NetWeaver Flaw that Enables Memory Corruption | Cryptika Cybersecurity

One of multiple Apache Tomcat vulnerabilities affecting SAP Commerce Cloud.

onapsisNews

Jul 14, 2026

SAP Security Patch Day for July 2026 - Onapsis

One of multiple Apache Tomcat vulnerabilities affecting SAP Commerce Cloud and apparently also SAP Data Hub deployments referenced by the note.

security weekNews

Jun 18, 2026

Atlassian, Splunk Patch Critical Vulnerabilities - SecurityWeek

A critical-severity vulnerability in Apache Tomcat affecting third-party dependencies used in Atlassian products.

+1 more in the timeline

What this page doesn’t show

The version that knows your environment.

This page is what’s public. Mallory adds the parts that aren’t: which of your assets are affected, which adversaries are exploiting it right now, which detections to deploy, and what to do tonight.

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Exposure mapping

Query your assets running an affected version, and investigate the blast radius.

Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity4

Community discussion across Reddit, Mastodon, and other social sources.

EXTERNAL REFERENCES

MITRE CVE

cve.org · CVE-2026-43515

NVD

nvd.nist.gov/vuln/detail/CVE-2026-43515

MITRE CWE · CWE-863

cwe.mitre.org

Vendor Advisory

lists.apache.org/thread/746nxfxod0wsocxtmv8pb8nkgmwpc6bb

Third Party Advisory

openwall.com/lists/oss-security/2026/05/12/11

Improper Authorization in Apache Tomcat security constraint method handling

IdentifiersCVE-2026-43515CWE-863