High severity · published Aug 27, 2026
CVE-2026-5680
Undertow-core: undertow: denial of service via websocket permessage-deflate processing
7.5
CVSS
1.1%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.1% · higher than 65% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
RH
Red Hat Data Grid 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 10 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 8 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 8.1 for RHEL 9 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform 8.1.8.GA · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat JBoss Enterprise Application Platform Expansion Pack · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Process Automation 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat Single Sign-On 7 · Red Hat
All versions, or not specified · source: vendor
RH
Red Hat build of Apache Camel for Spring Boot 4 · Red Hat
All versions, or not specified · source: vendor
Affected product
RH
Red Hat build of Apache Camel for Spring Boot 4
Red Hat
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5680
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-5680
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:70228
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:70229
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:70230
vendor-advisory
https://access.redhat.com/errata/RHSA-2026:70277
vdb-entry
https://access.redhat.com/security/cve/CVE-2026-5680
issue-tracking
https://bugzilla.redhat.com/show_bug.cgi?id=2455350
More from Red Hat build of Apache Camel for Spring Boot 4
9.1
CVE-2026-28369
Undertow: undertow: request smuggling via malformed http request headers
9.1
CVE-2026-28367
Undertow: undertow: request smuggling via `\r\r\r` as a header block terminator
9.1
CVE-2026-28368
Undertow: undertow: request smuggling via inconsistent header parsing
8.2
CVE-2026-93569
Io.netty/netty-codec-http2: http/1 absolute-form host mismatch is translated to http/2 :authority, overriding the request-target authority
8.1
CVE-2026-84218
Org.jolokia/jolokia-core: incomplete jndi denylist in jolokia jsr-160 proxy (bypass of cve-2018-1000130 fix)