CVE-2026-107937

Apache CXF: The attachment header size and count limits can be bypassed, which allows denial of service through memory exhaustion.

HIGH
7.5
CVSS Score
Published: October 9, 2026 at 10:19 AM UTC
Updated: October 16, 2026 at 06:10 PM UTC
1 product affected across 1 vendorCXF

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

95%
v < 3.6.134.0.0 ≤ v < 4.1.94.2.0 ≤ v < 4.2.44.0.04.2.0

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Vendor AdvisoryIssue TrackingMailing List
Source: cverecord
https://lists.apache.org/thread.html/x9twtpv3d04qj83t6w9xkh9y2q28zztj
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.openwall.com/lists/oss-security/2026/10/09/12

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-770

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