CVE-2026-77756

Publication date 24 September 2026

Last updated 24 September 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

3.7 · Low

Score breakdown

Description

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when Tomcat is located behind a reverse proxy. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121. The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.67 through 8.5.100. Other unsupported versions may also be affected. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

Read the notes from the security team

Status

Package Ubuntu Release Status
tomcat6 26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
16.04 LTS xenial
Not affected
14.04 LTS trusty
Needs evaluation
tomcat7 26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation
tomcat8 26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy Not in release
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
tomcat9 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
tomcat10 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy Not in release
tomcat11 26.04 LTS resolute
Needs evaluation
24.04 LTS noble Not in release
22.04 LTS jammy Not in release

Notes

ebarretto

xenial tomcat6 only builds libservlet2.5-java, not the Tomcat server binaries bionic tomcat7 only builds libservlet3.0-java, not the Tomcat server binaries xenial tomcat6 only builds libservlet2.5-java, not the Tomcat server binaries bionic tomcat7 only builds libservlet3.0-java, not the Tomcat server binaries xenial tomcat6 only builds libservlet2.5-java, not the Tomcat server binaries bionic tomcat7 only builds libservlet3.0-java, not the Tomcat server binaries

Severity score breakdown

CVSS version: CVSS v3.0

Base score 3.7 · Low

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

References

Other references

Access our resources on patching vulnerabilities