What is CVE-2026-103119?

CVE-2026-103119 is a critical-severity vulnerability in Apache Software Foundation Tomcat, classified under Buffer Under-read. CVSS score: 9.1/10. Published 2026-10-20.

How severe is CVE-2026-103119?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Apache Software Foundation Tomcat

CVE-2026-103119

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.

Published 2026-10-20 · last modified 2026-10-20.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Apache Software Foundation Tomcat

Weakness classification (CWE)

CWE-127 — Buffer Under-read

References

lists.apache.org/thread.html/sk2cg4k077fwcqbm6tqz2n700nq06h80 (vendor-advisory)

Frequently asked questions

What is CVE-2026-103119?: CVE-2026-103119 is a critical-severity vulnerability in Apache Software Foundation Tomcat, classified under Buffer Under-read. CVSS score: 9.1/10. Published 2026-10-20.
How severe is CVE-2026-103119?: Critical severity. CVSS v3 base score is 9.1 out of 10.