How severe is CVE-2026-10858?

CVE-2026-10858 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-10858 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-10858?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-10858 published?

CVE-2026-10858 was published on 2026-09-18 and last updated on 2026-09-19.

CVE-2026-10858

CVE-2026-10858 is a critical-severity vulnerability with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 0% (26th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-122
Published: 2026-09-18
Last modified: 2026-09-19

Description

IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40 could allow an authenticated attacker to cause a denial of service or potentially execute arbitrary code due to a heap buffer underflow when processing multi-segment messages.

Frequently asked questions

What is CVE-2026-10858?: IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40 could allow an authenticated attacker to cause a denial of service or potentially execute arbitrary code due to a heap buffer underflow when processing multi-segment messages.
How severe is CVE-2026-10858?: CVE-2026-10858 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-10858 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (26th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-10858?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-10858 published?: CVE-2026-10858 was published on 2026-09-18 and last updated on 2026-09-19.

References

https://www.ibm.com/support/pages/node/7287704

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