CVE-2026-86350: Apache Tomcat: Regression in fix for CVE-2026-41293 can trigger request header mix-up
Apache Software Foundation · Apache Tomcat
Vendor fix available · Affected: Apache Software Foundation Apache Tomcat · Exploitation: public proof of concept (unverified)
ExploitationProof of concept public
Not in CISA KEV as of catalogue 2026.11.13 (13 Nov)
- In CISA KEV: not seen
- Exploited (reported): not seen
- Scanning observed: not seen
- Proof of concept public1 public GitHub repository (unverified), listed by PoC-in-GitHub25 Sep
- Not established: not seen
Higher than 42% of scored CVEs
DescriptionNVD
Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache Tomcat caused by a regression in fix for CVE-2026-41293 can trigger request header mix-up. This issue affects Apache Tomcat: from 11.0.22 through 11.0.25, from 10.1.55 through 10.1.59, from 9.0.118 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Published
- September 2026
What changed
- PoC-in-GitHub lists 1 public GitHub repository (unverified) PoC-in-GitHub
Coverage1 article · 1 outlet
First in our coverage: SecurityOnline, 23 Sep.
- Apache Tomcat 11.0.26 Fixes 15 Flaws Enabling Request Smuggling and DoSSecurityOnline · first in our coverage · mentions it in passing
New articles also arrive in the RSS feed.