CVE Intelligence
Medium Injection

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

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.

Published Oct 19, 2026 · Updated Oct 19, 2026 · Sources: CVE Program (cve.org) e CISA ADP, NIST National Vulnerability Database · CNA: apache

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Apache Software Foundation
Camel
CVSS base
6.5
Medium · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Camel).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Apache Software Foundation Camel ≥ 4.0.0 and < 4.18.5≥ 4.19.0 and < 4.22.1 Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.5 CVSS 3.1 Medium 2.2 4.2 security@apache.org via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — apache via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N (score shown at the top: security@apache.org)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-611 · XML External Entity (XXE)

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Source status changed · Received → Awaiting Analysis
    Oct 19, 2026 · NIST National Vulnerability Database
  • SSVC assessment updated
    Oct 19, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · Published → Received
    Oct 19, 2026 · NIST National Vulnerability Database
  • Record published
    Oct 19, 2026
  • CVSS changed · 6.5
    Oct 19, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Published
    Oct 19, 2026 · CVE Program (cve.org) e CISA ADP
  • Record created in this database
    Oct 19, 2026 · CVE Program (cve.org) e CISA ADP
  • CVE published
    Oct 19, 2026 · apache

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 19, 2026 – Oct 19, 2026

References

5 on the record

Elsewhere on this site

Apache Software Foundation
every CVE for this vendor
Injection
same class
CWE-611
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-88900 Apache Camel: Camel-JGroups: Unsafe Java Deserialization of Cluster Messages in the JGroups Consumer Can Lead to Remote Code Execution 1d
  • CVE-2026-85317 Apache Camel: Camel-HTTP OAuth2 Token Confusion via an Under-Keyed JVM-Global Token Cache 1d
  • CVE-2026-88901 Apache Camel: Camel-Smooks XML External Entity Processing, external entities resolved by default 1d
  • CVE-2026-85314 Apache Camel: Camel-Mail Header Injection via Unfiltered mail.smtp Headers in the MimeMultipart Data Format (Incomplete Fix of CVE-2026-46584) 1d
  • CVE-2026-85313 Apache Camel: Camel-Jetty Cross-Origin Credential Exposure via Allow-All CrossOriginFilter Defaults When enableCORS Is Set 1d
  • CVE-2026-85300 Apache Camel: Camel-PQC Private Key Disclosure via Key Material Written with Default File Permissions 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-91858 is "Apache Camel: Camel-FOP Resolves External DTDs and Entities From Untrusted XSL-FO Input When a Third-Party JAXP TransformerFactory Is Present", rated Medium. It affects Camel (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 6.5 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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