CVE-2026-5680
A flaw was found in Undertow.
Published Aug 27, 2026 · updated Oct 14, 2026
A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using exponential doubling, resulting in a Denial of Service (DoS) for the affected application.
Timeline
Detection, updates, and resolution for this record.
Aug 27, 2026 · NIST NVD
Detected
A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using exponential doubling, resulting in a Denial of Service (DoS) for the affected application.
Oct 14, 2026 · NIST NVD
Updated
A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using exponential doubling, resulting in a Denial of Service (DoS) for the affected application.
Sources
- CVE.orgCVE-2026-5680
Official CVE identifier
cve.org - FIRST EPSSCVE-2026-5680
30-day exploitation probability 1.1%
first.org - NIST NVDCVE-2026-5680
A flaw was found in Undertow. A remote attacker could exploit this vulnerability by sending specially crafted WebSocket messages with permessage-deflate negotiated. This could lead to excessive memory consumption due to the PerMessageDeflateFunction.largerBuffer() method using ex
nvd.nist.gov