MQ: Improper Restriction of XML External Entity Reference
CVE-2026-13271 is a high-severity improper restriction of XML external entity reference vulnerability in MQ from IBM, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected MQ versions: 9.2.0.0 through 9.2.0.44; 9.3.0.0 through 9.3.0.42; 9.4.0.0 through 9.4.0.26, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.23% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of MQ you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| IBM | MQ | 9.2.0.0 through 9.2.0.44; 9.3.0.0 through 9.3.0.42; 9.4.0.0 through 9.4.0.26; 9.4.0.0 through 9.4.5.1; 10.0.0.0 through 10.0.0.5 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N. Scored by CNA (us.ibm.com).
Official description
IBM MQ 9.2.0.0 through 9.2.0.44 LTS, 9.3.0.0 through 9.3.0.42 LTS, 9.4.0.0 through 9.4.0.26 LTS, 9.4.0.0 through 9.4.5.1 CD, and 10.0.0.0 through 10.0.0.5 LTS and CD Managed File Transfer could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper restriction of XML external entity references in command queue processing.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Restriction of XML External Entity Reference
The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.
How developers prevent this class of flaw
- Many XML parsers and validators can be configured to disable external entity expansion.
More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in MQ
- 7.1 High severity
- 8.8 High severity
- 7.1 High severity
- 7.1 High severity
- 7.5 High severity
- 8.8 High severity
Recent Improper Restriction of XML External Entity Reference vulnerabilities
- 8.2 High severity
- 7.2 High severity
- 8.2 High severity
- 8.2 High severity
- 7.1 High severity
- 7.5 High severity
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