ZeroHour

CVE-2026-29146

1
CVSS 3.1
7.5 high
EPSS
9%p95
Published
()
Modified
Description

Padding Oracle vulnerability in Apache Tomcat's EncryptInterceptor with default configuration. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 10.0.0-M1 through 10.1.52, from 9.0.13 through 9..115, from 8.5.38 through 8.5.100, from 7.0.100 through 7.0.109. Users are recommended to upgrade to version 11.0.19, 10.1.53 and 9.0.116, which fixes the issue.

Vendors
apache
Products
tomcat
Weakness
CWE-209, CWE-642, CWE-1240
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

In the news

CVE-2026-34486: Apache Software Foundation Apache Tomcat

CISA added CVE-2026-34486, an actively exploited Apache Tomcat EncryptInterceptor bypass enabling unauthenticated deserialization RCE, to its KEV catalog.

CVE-2026-34486 allows bypass of Apache Tomcat's EncryptInterceptor, a flaw introduced by the fix for padding-oracle issue CVE-2026-29146 in Tribes cluster encryption. CISA added the flaw to the Known Exploited Vulnerability catalog on August 4, 2026, alongside actively exploited Langflow and N-central flaws, with remediation required under BOD 26-04 guidance. Official patches and workarounds are available, and reporting notes unauthenticated remote code execution through Java deserialization on the Tribes receiver port 4000.

CVE-2026-34486: Apache Tomcat EncryptInterceptor Fail-Open Bypass

Technical analysis shows CVE-2026-34486 is a one-line fail-open regression in Tomcat Tribes enabling unauthenticated RCE via Java deserialization.

CVE-2026-34486 is a fail-open regression in Tomcat's Tribes EncryptInterceptor, introduced while fixing the CVE-2026-29146 padding-oracle flaw; Apache rated it Important and NVD scores it 7.5 High. Decryption failures are now forwarded to an unfiltered ObjectInputStream, and public PoC repositories demonstrate unauthenticated RCE on default port 4000 when clustering, the EncryptInterceptor, a reachable receiver and deserialization gadgets are all present. Affected releases 9.0.116, 10.1.53 and 11.0.20 are fixed in 9.0.117, 10.1.54 and 11.0.21; Tomcat 8.5 is unaffected.

CVE-2026-34486: Apache Tomcat Auth Bypass Vulnerability

SentinelOne details CVE-2026-34486, an Apache Tomcat EncryptInterceptor bypass exposing unencrypted cluster communications, with patches and workarounds available.

CVE-2026-34486 stems from an incomplete fix for CVE-2026-29146, letting network-positioned attackers bypass the EncryptInterceptor and read plaintext Tomcat cluster traffic, including session and application data between nodes. Affected versions 9.0.116, 10.1.53 and 11.0.20 are fixed in 9.0.117, 10.1.54 and 11.0.21. Workarounds include network-level encryption such as IPsec or VPN tunnels and isolating cluster communications to secured network segments.