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CVE.org (no NVD analysis yet)· CNA apache

CVE-2026-107937: Apache CXF: The attachment header size and count limits can be bypassed, which allows denial of service through memory exhaustion.

HighCVSS 7.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.55% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Apache Software Foundation Apache CXF 3.6.13, 4.1.9, 4.2.4.

Low priority for now. Upgrade to Apache Software Foundation Apache CXF 3.6.13, 4.1.9, 4.2.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Oct 9, 2026
Updated
Oct 16, 2026
EPSS
0.5% · 46th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-107937

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
apachecxf

Versions reported by the vendor

Affected version ranges reported by the assigning authority (apache). Independent of NVD's CPE analysis and usually ahead of it.

  • Apache Software Foundation Apache CXF

    • 4.2.0 and later · before 4.2.4affected · semver
    • 4.0.0 and later · before 4.1.9affected · semver
    • before 3.6.13affected · semver

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • apache cxfbefore 3.6.13
  • apache cxf4.0.0 and later · before 4.1.9
  • apache cxf4.2.0 and later · before 4.2.4

Same product

apache: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-12419Apache CXF before 3.3.4 and 3.2.11 provides all of the components that are required to build a fully fledged OpenId Connect service.
    43Plan
  • CVE-2010-2076Apache CXF 2.0.x before 2.0.13, 2.1.x before 2.1.10, and 2.2.x before 2.2.9, as used in Apache ServiceMix, Apache Camel, Apache Chemistry…
    42Plan
  • CVE-2012-2379Apache CXF 2.4.x before 2.4.8, 2.5.x before 2.5.4, and 2.6.x before 2.6.1, when a Supporting Token specifies a child WS-SecurityPolicy 1.1…
    41Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-68481Aug 6, 2026 · Apache CXF: Revocation bypass in DefaultEncryptingOAuthDataProvider
    30Monitor
  • ← EarlierCVE-2026-100227Oct 9, 2026 · Apache CXF: XML Signature wrapping in JAX-RS XML Security
    30Monitor
  • Later →CVE-2026-107938Oct 9, 2026 · Apache CXF: The Netty HTTP client transport does not perform TLS hostname verification.
    36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Apache Software Foundation Apache CXF3.6.13Vendor (CNA)
Apache Software Foundation Apache CXF4.1.9Vendor (CNA)
Apache Software Foundation Apache CXF4.2.4Vendor (CNA)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 13, 2026+35 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-5422564 days apartApache CXF: Denial of Service attack via large attachments
    30Monitor

Not on record for this CVE: patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-770 · Allocation of Resources Without Limits or Throttling

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. CVSS— → 7.5
  2. Severity— → high
  3. SSVC exploitation— → none
  4. Exploit maturity— → none
  5. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records