IBM MQ XMS .NET client is affected by an arbitrary code execution vulnerability
Affects the .NET messaging component (XMS .NET client) of IBM MQ 9.2, 9.3, 9.4 and 10.0 releases up to the last affected builds listed. Fixed by cumulative security update 9.2.0.46.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 9.2.0.46
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. Affects the .NET messaging component of IBM MQ (XMS .NET client) Affected IBM MQ versions include 9.2.0.0 to 9.2.0.44 LTS, 9.3.0.0 to 9.3.0.42 LTS, 9.4.0.0 to 9.4.0.26 LTS, 9.4.0.0 to 9.4.5.1 CD, and 10.0.0.0 to 10.0.0.5 LTS and CD
- Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
- Exposure8/25Specific setups only, reachable over the network
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 66 if added to CISA KEV
- Would score about 61 if CISA's SSVC rates exploitation active
- Would score about 23 if CISA's SSVC rates it automatable
CVE-2026-10859 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.5 (high) and affects MQ; fixed in 9.2.0.46.
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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? →
- 16/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Specific setups only
- Fix
- Fixed in 9.2.0.46
- 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
IBM MQ XMS .NET client, a component used by consumer applications, is affected by an arbitrary code execution flaw caused by insecure deserialization of ObjectMessage payloads. An attacker with low-privilege login can reach it remotely over the network, and no user action is needed, to run arbitrary code on the consuming application.
Read the original 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 could allow an authenticated attacker to execute arbitrary code on consumer applications due to insecure deserialization of ObjectMessage payloads.
What to do
Check whether your setup matches what the bug needs.
Affects the .NET messaging component of IBM MQ (XMS .NET client) Affected IBM MQ versions include 9.2.0.0 to 9.2.0.44 LTS, 9.3.0.0 to 9.3.0.42 LTS, 9.4.0.0 to 9.4.0.26 LTS, 9.4.0.0 to 9.4.5.1 CD, and 10.0.0.0 to 10.0.0.5 LTS and CDUpgrade to a fixed version: 9.2.0.46.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- IBM MQ
From 9.2.0.0 · through 9.2.0.44; From 9.3.0.0 · through 9.3.0.42; From 9.4.0.0 · through 9.4.0.26; From 9.4.0.0 · through 9.4.5.1; From 10.0.0.0 · through 10.0.0.5
Evidence 1
- Patch
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-10859
Is CVE-2026-10859 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
What does this mean?
An authenticated attacker could execute arbitrary code on consumer applications that use the affected .NET messaging component of IBM MQ.Source: ibm.com
Which versions are affected by CVE-2026-10859?
MQ: from 9.2.0.0 through 9.2.0.44; from 9.3.0.0 through 9.3.0.42; from 9.4.0.0 through 9.4.0.26; from 9.4.0.0 through 9.4.5.1; from 10.0.0.0 through 10.0.0.5.Source: cve.now feed data
Am I affected, and how do I check?
Affected IBM MQ versions are 9.2.0.0 to 9.2.0.44 LTS, 9.3.0.0 to 9.3.0.42 LTS, 9.4.0.0 to 9.4.0.26 LTS, 9.4.0.0 to 9.4.5.1 CD, and 10.0.0.0 to 10.0.0.5 LTS and CD, for installs that include the XMS .NET client component. Check the installed IBM MQ version and whether the .NET messaging component is installed.Source: ibm.com
How do I fix CVE-2026-10859?
Apply cumulative security update 9.2.0.46.Source: ibm.com