CVE-2026-95616 Apache WSS4J: Unauthenticated denial of service via integer overflow in DER parsing of X.509 certificate extensions

High 7.5 Published 30 Sep 2026 Updated 30 Sep 2026

Unauthenticated attackers can cause denial of service via memory exhaustion by sending crafted X.509 certificates with oversized extension lengths.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-95616?

CVE-2026-95616 is a high-severity vulnerability in Apache WSS4J, published on 30 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

An integer overflow in WSS4J's DER bounds check lets an oversized allocation pass validation. An unauthenticated attacker can send a SOAP message carrying an X.509 certificate whose SubjectKeyIdentifier extension declares a length of 0x7FFFFFFF; WSS4J decodes this while resolving the signature's key reference, before the message is authenticated, so an eleven-byte extension triggers a 2 GB allocation. Repeated requests exhaust server memory. Users are recommended to upgrade to versions 4.0.2 or 3.0.6 or 2.4.4, which fix this issue.

Weakness: CWE-190

Which versions are affected by CVE-2026-95616?

It affects 1 product.

Products include Apache Wss4j.

How do I fix CVE-2026-95616?

No fix has been published for CVE-2026-95616 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-95616 being exploited?

There is no known exploitation of CVE-2026-95616 in the wild and no public exploit code.

Sources

Also known as DEBIAN-CVE-2026-95616, GHSA-9gjf-54jg-6353, UBUNTU-CVE-2026-95616.