IBM MQ Appliance is affected by an improper validation vulnerability
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Not reported
Do first: Apply the patch listed under Evidence.
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure3/25Reachable over the network · Data gap: No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity5.4/10CVSS 5.4
- No patch0/5No signal
What would change the score
- Would score about 63 if added to CISA KEV
- Would score about 58 if CISA's SSVC rates exploitation active
- Would score about 27 if advisories confirm default setups are exposed
CVE-2026-12538 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.4 (medium) and affects MQ Appliance; a fix or patch is referenced.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 8/100 · provisional
- Fix
- Fix or patch referenced
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The IBM MQ Appliance has an improper validation flaw in how it checks the length fields of message header structures. Remotely, by an attacker with low-privilege login credentials, the flaw can be used to obtain sensitive information or to cause a denial of service.
Read the original description
IBM MQ 9.4.0.0 to 9.4.0.26, 9.4.1.0 to 9.4.5.3, and 10.0.0.1 to 10.0.0.5 could allow an authenticated attacker to obtain sensitive information or cause a denial of service due to improper validation of message header structure length fields.
What to do
Apply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- IBM MQ Appliance
From 9.4.0.0 · through 9.4.0.26; From 9.4.1.0 · through 9.4.5.3; From 10.0.0.1 · through 10.0.0.5
Evidence 1
- Patch
Corrections
None so far.
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Questions about CVE-2026-12538
Is CVE-2026-12538 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-12538?
MQ Appliance: from 9.4.0.0 through 9.4.0.26; from 9.4.1.0 through 9.4.5.3; from 10.0.0.1 through 10.0.0.5.Source: cve.now feed data