9.1

CVE-2026-103119: Apache Tomcat: AJP response mix-up

Awaiting analysis
AliasesDEBIAN-CVE-2026-103119UBUNTU-CVE-2026-103119
Published 20-10-2026Last modified 20-10-2026

Vulnerability summary

CVE-2026-103119 is a critical (CVSS 9.1) Buffer Under-read vulnerability in apache software foundation apache tomcat. EPSS estimates a 0.59% chance of exploitation in the next 30 days, higher than 48% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.59%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
OPENSUSE-SU-2026:12256-1

Timeline

  1. 20-10-2026
    PublishedVulnerability first disclosed.
  2. 20-10-2026
    Last modifiedVulnerability information updated.

Description

Buffer under-read vulnerability in Apache Tomcat meant that a large non-blocking write could result in the response body being split between the current request and the next request received on that connection leading most likely to failure of the second request and possibly leakage of data from the first response to the second. This issue affects Apache Tomcat: from 11.0.0-M25 through 11.0.26. Users are recommended to upgrade to version 11.0.27, which fixes the issue.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.59%

Chance of exploitation in the next 30 days

Percentile

48%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

21-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu6 products
  • tomcat10All versions (No fix recorded)
  • tomcat11All versions (No fix recorded)
  • tomcat6All versions (No fix recorded)
  • tomcat7All versions (No fix recorded)
  • tomcat8All versions (No fix recorded)
Apache software foundation1 product
Debian1 product
  • tomcat11All versions (No fix recorded)

3 vendors · 8 products

References

6 links