Vulnerability · Published Aug 11, 2026 · Assigned by redhat
CVE-2026-15561Undertow-core: oom via missing limits in chunked trailer in eap's undertow
High 7.5
In plain English
A high-severity resource allocation without limits in Red Hat JBoss Enterprise Application Platform 7.4.25 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.7%top 46.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
A flaw was found in EAP's undertow http/1.1 chunked-transfer decoder. missing limits on size and count would allow an attacker to use an unauthenticated connection to drive the JVM to an OutOfMemory error, stopping all deployments on the listener, and achieving Denial of Service.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:14 | undertow | no fix listed | DEBIAN-CVE-2026-15561 |
| Ubuntu:26.04:LTS | undertow | no fix listed | UBUNTU-CVE-2026-15561 |
| Ubuntu:26.10 | undertow | no fix listed | UBUNTU-CVE-2026-15561 |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- RHSA-2026:53644 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:53806 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70228 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70229 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70230 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:70277 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-15561 vdb-entry, x_refsource_REDHAT
- RHBZ#2483133 issue-tracking, x_refsource_REDHAT