Security readout for executives and security teams
Plain-English summary
CVE-2026-24733 is an Apache Tomcat flaw where unusual HTTP/0.9 handling could bypass a specific access rule. It matters if an application allowed HEAD requests to a URI while denying GET requests. Apache rates it medium and provides fixed Tomcat versions.
Executive priority
Treat as a moderate-priority patching item. Prioritize internet-facing Tomcat systems and applications using method-specific access controls. The business risk is unauthorized access to protected resources in narrow configurations, not broad server takeover based on current public information.
Technical view
Tomcat did not restrict HTTP/0.9 requests to GET. A specification-invalid HEAD request using HTTP/0.9 could be treated in a way that bypassed security constraints configured to allow HEAD but deny GET for the same URI. Affected branches are 11.0.0-M1 through 11.0.14, 10.1.0-M1 through 10.1.49, and 9.0.0.M1 through 9.0.112.
Likely exposure
Exposure is likely limited to Tomcat deployments on affected versions with security constraints that allow HEAD but deny GET for a URI. Internet-facing Tomcat services with such configurations deserve prompt review. Older end-of-life Tomcat versions are also reported affected.
Exploitation context
The source bundle does not report active exploitation, and this CVE is not marked in KEV. The attack is network-reachable, unauthenticated, and low complexity per CVSS, but depends on a specific Tomcat constraint configuration involving HEAD and GET handling.
Researcher notes
This is CWE-20 improper input validation involving HTTP/0.9 method handling and Tomcat security constraints. The key condition is an allowed HEAD method with denied GET on a URI. No exploit code or exploitation-in-the-wild evidence is included in the provided sources.
Mitigation direction
- Upgrade Tomcat 11.x to 11.0.15 or later.
- Upgrade Tomcat 10.1.x to 10.1.50 or later.
- Upgrade Tomcat 9.0.x to 9.0.113 or later.
- Review vendor guidance for older end-of-life Tomcat versions.
- Audit security constraints that allow HEAD while denying GET.
Validation and detection
- Inventory all Apache Tomcat versions in production and staging.
- Identify deployments running affected Tomcat version ranges.
- Review web.xml and related security constraints for HEAD-allowed, GET-denied URI patterns.
- Confirm upgraded instances report fixed Tomcat versions.
- Check vendor advisory for any updated remediation details.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-24733 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N3.92.5Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://lists.apache.org/thread/6xk3t65qpn1myp618krtfotbjn1qt90fCVE reference · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.