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Fencer Intel
high 7.5

CVE-2026-107937 json

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

published last mo. modified 24d ago also EUVD-2026-95702

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 46%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache CXF 3.6.13, 4.1.9, 4.2.4

Is CVE-2026-107937 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-107937 updated cvss 7.5

org.apache.cxf/cxf-core: Apache CXF: Denial of Service via large multipart attachment headers

  • Red Hat build of Apache Camel 4 for Quarkus 3 cxf-core 4.1.7.rhbac-redhat-00003 Red Hat build of Apache Camel for Spring Boot 4 cxf-core 4.1.7.rhbac-redhat-00003
    affected: workaround, no fix available
  • Red Hat JBoss Enterprise Application Platform 7 cxf-core 4.1.7.rhbac-redhat-00003, jboss-eap-7/eap74-els-openjdk8-openshift-rhel8, jboss-eap-7/eap74-els-openjdk11-openshift-rhel8, jboss-eap-7/eap74-els-openjdk17-openshift-rhel8
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat JBoss Enterprise Application Platform 8 cxf-core 4.1.7.rhbac-redhat-00003
    affected: workaround, no fix available
  • Red Hat JBoss Web Server 5 cxf-core 4.1.7.rhbac-redhat-00003
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Single Sign-On 7 cxf-core 4.1.7.rhbac-redhat-00003
    affected: workaround, no fix planned “Will not fix”
  • Red Hat Build of Apache Camel 3.33.4.SP3 cxf-core 4.1.9.rhbac-redhat-00001
    fixed: vendor fix RHSA-2026:95622
  • Red Hat Build of Apache Camel 3.33.4.SP3 jimfs 1.1, jna 5.8.0, bcel 6.7.0, gax 2.74.1, icu4j 78.2, joni 2.2.6, +1616 more
    not affected: vulnerable code not present
  • Red Hat Fuse 7 cxf-core 4.1.7.rhbac-redhat-00003
    not affected: vulnerable code not in execute path
show 1 more
  • Red Hat JBoss Enterprise Application Platform Expansion Pack cxf-core 4.1.7.rhbac-redhat-00003
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
25d ago

Exploit prediction

0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Apache Software Foundation Apache CXF

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.