CVE-2026-34486 Apache Tomcat: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Aug 7, 2026
What to do
- Install Apache's security update for Tomcat. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Apache Tomcat Missing Encryption of Sensitive Data Vulnerability
- Product
- Apache Tomcat
- CISA description
- Apache Tomcat contains a missing encryption of sensitive data vulnerability that allows the bypass of the EncryptInterceptor. This vulnerability can be chained with CVE‑2025‑24813.
- Type of flaw
- Software flaw (CWE-311)
- Confirmed exploited
- Aug 4, 2026
- US federal patch deadline
- Aug 7, 2026
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Answering about CVE-2026-34486 ·
Questions about CVE-2026-34486
Is CVE-2026-34486 being exploited?
Yes. CISA added CVE-2026-34486 to its Known Exploited Vulnerabilities catalog on Aug 4, 2026, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2026-34486?
Install Apache's security update for Tomcat. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2026-34486?
Only if you use Apache Tomcat. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.