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

CVE-2026-91858: Apache Camel: Camel-FOP Resolves External DTDs and Entities From Untrusted XSL-FO Input When a Third-Party JAXP TransformerFactory Is Present

Noroxi assessment

Priority: Monitor (action score 26/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.30% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Apache Software Foundation Apache Camel 4.18.5, 4.22.1.

Low priority for now. Upgrade to Apache Software Foundation Apache Camel 4.18.5, 4.22.1 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

FopProducer transforms the incoming XSL-FO message body by creating a javax.xml.transform.TransformerFactory through TransformerFactory.newInstance() and enabling only FEATURE_SECURE_PROCESSING before running an identity transform over the body. On the JDK's built-in transformer, that feature alone already empties the accessExternalDTD and accessExternalStylesheet limits, so an external DTD or entity is refused. When a third-party JAXP TransformerFactory such as Saxon-HE is on the classpath, for example because the application also uses camel-xslt-saxon or camel-saxon, TransformerFactory.newInstance() returns that implementation instead, and FEATURE_SECURE_PROCESSING on its own does not restrict external resource access on it. A DOCTYPE with an external subset, or an external general entity, declared in the XSL-FO document is then resolved and expanded while the body is transformed. An external sender whose XSL-FO reaches a fop producer could therefore read files readable by the Camel process and cause the process to issue requests to hosts the document names. camel-fop does not bring such a factory itself, and excludes Xalan, so a default deployment using the JDK transformer is not affected; the issue is reachable only where another component has placed an alternative JAXP TransformerFactory on the classpath. Releases on the 4.14.x line and earlier reached end of life before this issue was resolved and do not receive a fix.

MediumCVSS 6.5 · v3.1—Proof of concept Fix available
Published
Oct 19, 2026
Updated
Oct 19, 2026
EPSS
0.3% · 23th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · apache
6.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

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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.

—

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 Camel

    • 4.0.0 and later · before 4.18.5affected · maven
    • 4.19.0 and later · before 4.22.1affected · maven

Same product

apache software foundation: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-78162Apache Camel: Camel-Hazelcast Managed Instances Missing Java Deserialization Filter (Incomplete Fix for CVE-2026-43865)
    40Plan
  • CVE-2026-88900Apache Camel: Camel-JGroups: Unsafe Java Deserialization of Cluster Messages in the JGroups Consumer Can Lead to Remote Code Execution
    35Monitor
  • CVE-2026-83531Apache Camel: Camel-Dynamic-Router Control Endpoint Compiles Predicate Expressions Supplied by Control Messages
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-85317Oct 19, 2026 · Apache Camel: Camel-HTTP OAuth2 Token Confusion via an Under-Keyed JVM-Global Token Cache
    19Monitor
  • ← EarlierCVE-2026-88901Oct 19, 2026 · Apache Camel: Camel-Smooks XML External Entity Processing, external entities resolved by default
    32Monitor
  • Later →CVE-2026-101259Oct 26, 2026 · Apache Camel: Camel-CoAP Information Disclosure via Unmuted Consumer Exceptions
    21Monitor

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 Camel4.18.5Vendor (CNA)
Apache Software Foundation Apache Camel4.22.1Vendor (CNA)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02026-10-21

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. First PoC+2 d
  4. TodayOct 28, 2026+9 d
EPSS, last 120 days

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

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

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-2026-889010 days apartApache Camel: Camel-Smooks XML External Entity Processing, external entities resolved by default
    32Monitor
  • CVE-2026-852500 days apartApache Camel: Camel-XPath XML External Entity Processing and File Disclosure via the documentType=InputSource Option
    30Monitor
  • CVE-2026-908857 days apartApache Camel: Camel-Saxon XML External Entity Processing - XQueryBuilder Parsed a Message Body That Was Already a javax.xml.transform.Source With Saxon's Defaul
    30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
high · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-611 · Improper Restriction of XML External Entity Reference

CVSS vector

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

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.

ATT&CK techniques

—

Change log

  1. Exploit maturitynone → poc
  2. SSVC exploitation— → none
  3. Exploit maturity— → none
  4. Fix✗ → ✓

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

References

Show all references (4 more)

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

All records