CVE-2026-115721: Apache Vysper: Unbounded allocation

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-26 · updated 2026-10-26

Description

**UNSUPPORTED WHEN ASSIGNED** Unbounded allocation in XML parsing in Apache Vysper; all versions, may lead to an out of memory condition. This issue affects all versions of Apache Vysper. Apache Vysper is an XMPP (Jabber) server library. As this project is retired, we do not plan to release a version that fixes this issue. Users are recommended to find an alternative.

Affected products

Apache Software Foundation Apache Vysper: all versions

References

https://lists.apache.org/thread.html/d0bx15hjcs69gktk9tt25vgvk121c9vm
https://mina.apache.org/vysper-project/
http://www.openwall.com/lists/oss-security/2026/10/23/20

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