Review reviewHigh

CVE-2025-53114

cometd

CometD is a scalable comet implementation for web messaging. In versions 5.0.0 through 5.0.22, 6.0.0 through 6.0.18, 7.0.0 through 7.0.18, and 8.0.0 through 8.0.8, bad clients that always send a fixed batch value when the server is using the acknowledgement extension may cause the unacknowledged message queue to grow indefinitely, eventually causing an `OutOfMemoryError`. Versions 5.0.23, 6.0.19, 7.0.19, and 8.0.9 patch the issue. As a workaround, disable the acknowledgement extension.

CVSS: 7.5
EPSS: 0.68%
CISA KEV: Not listed
Published: 2026.06.19

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.68%

Technical severityCVSS 7.5

Vulnerability overview

Affected product and versions

Product: cometd
Affected versions: >= 5.0.0, < 5.0.23, >= 6.0.0, < 6.0.19, >= 7.0.0, < 7.0.19, >= 8.0.0, < 8.0.9
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that cometd and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE: CWE-400