Quick answers
- Is CVE-2026-15561 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-15561 being exploited in the wild.
- How severe is CVE-2026-15561?
- High severity, with a CVSS score of 7.5, published 11 August 2026.
- Which products and versions are affected?
- Red Hat Enterprise Application Platform <UNKNOWN>.
- Is there a fix for CVE-2026-15561?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-15561 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-15561?
- Check whether you run Red Hat Enterprise Application Platform at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability exists in Undertow's HTTP/1.1 chunked-transfer decoder, which lacks proper limits on the size and count of chunks. An unauthenticated attacker can exploit this via the network by sending HTTP requests with maliciously crafted chunked transfer encoding. The attack causes unbounded memory allocation in the JVM, triggering an OutOfMemory error that halts all deployments listening on the affected port. No authentication is required to exploit this vulnerability. Patches are expected to be available from Red Hat for affected Enterprise Application Platform versions.
Affected products
- Red Hat Enterprise Application Platform <UNKNOWN>
Timeline
- 2026-08-11: disclosed