In Apache CXF, the parser for multipart/MTOM attachment part headers did not fully enforce the configured attachment-max-header-size (default 300 characters) and attachment-headers-max-count (default 500) limits. The size limit was applied only to each physical line, not to a header value built from continuation lines or to the combined values of a repeated header. The count limit was checked against the number of distinct header names, not the total number of header lines. A remote, unauthenticated attacker could send a multipart request with very large folded or repeated part headers. The server would then allocate memory without bound, causing a denial of service.  Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
History

Fri, 16 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:apache:cxf:*:*:*:*:*:*:*:*

Thu, 15 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Sat, 10 Oct 2026 00:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-770
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Fri, 09 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
References

Fri, 09 Oct 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Apache
Apache cxf
Vendors & Products Apache
Apache cxf

Fri, 09 Oct 2026 11:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20
CWE-400

Fri, 09 Oct 2026 10:30:00 +0000

Type Values Removed Values Added
Description In Apache CXF, the parser for multipart/MTOM attachment part headers did not fully enforce the configured attachment-max-header-size (default 300 characters) and attachment-headers-max-count (default 500) limits. The size limit was applied only to each physical line, not to a header value built from continuation lines or to the combined values of a repeated header. The count limit was checked against the number of distinct header names, not the total number of header lines. A remote, unauthenticated attacker could send a multipart request with very large folded or repeated part headers. The server would then allocate memory without bound, causing a denial of service.  Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.
Title Apache CXF: The attachment header size and count limits can be bypassed, which allows denial of service through memory exhaustion.
References

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published: 2026-10-09T10:19:53.377Z

Updated: 2026-10-15T17:45:25.955Z

Reserved: 2026-10-09T09:12:15.139Z

Link: CVE-2026-107937

cve-icon Vulnrichment

Updated: 2026-10-09T11:07:52.472Z

cve-icon NVD

Status : Analyzed

Published: 2026-10-09T11:17:02.107

Modified: 2026-10-16T18:10:19.410

Link: CVE-2026-107937

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-09T10:19:53Z

Links: CVE-2026-107937 - Bugzilla