How severe is CVE-2026-18871?

CVE-2026-18871 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.

Is CVE-2026-18871 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-18871?

CVE-2026-18871 primarily affects Ibm Power System S1122 (9824-22a) Firmware. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-18871?

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

When was CVE-2026-18871 published?

CVE-2026-18871 was published on 2026-08-19 and last updated on 2026-08-25.

CVE-2026-18871

CVE-2026-18871 is a high-severity vulnerability in Ibm Power System S1122 (9824-22a) Firmware with a CVSS 3.x base score of 7.3. 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-121.

Key facts

Severity: High (CVSS 3.x base score 7.3)
EPSS exploit prediction: 0% (1st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-121
Affected product: Ibm Power System S1122 (9824-22a) Firmware
Published: 2026-08-19
Last modified: 2026-08-25

Description

IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80 is affected by a vulnerability in host firmware configuration parsing. An attacker with authenticated service-level access to the service processor can write specially crafted configuration data, causing the host firmware boot stack to crash with possible memory corruption during system initialisation, resulting in an integrity and availability impact to the managed system.

Frequently asked questions

What is CVE-2026-18871?: IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, and FW1060.00 through FW1060.80 is affected by a vulnerability in host firmware configuration parsing. An attacker with authenticated service-level access to the service processor can write specially crafted configuration data, causing the host firmware boot stack to crash with possible memory corruption during system initialisation, resulting in an integrity and availability impact to the managed system.
How severe is CVE-2026-18871?: CVE-2026-18871 has a CVSS 3.x base score of 7.3, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2026-18871 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-18871?: CVE-2026-18871 primarily affects Ibm Power System S1122 (9824-22a) Firmware. In total, 27 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-18871?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-18871 published?: CVE-2026-18871 was published on 2026-08-19 and last updated on 2026-08-25.

References

https://www.ibm.com/support/pages/node/7283238

Affected products (27)

cpe:2.3:o:ibm:power_system_s1122_\(9824-22a\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1122_\(9824-22a\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1124_\(9824-42a\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1124_\(9824-42a\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1122s_\(9824-22b\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1122s_\(9824-22b\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1114_\(9824-41b\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1114_\(9824-41b\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1122_\(9856-22h\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1122_\(9856-22h\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1124_\(9856-42h\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1124_\(9856-42h\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1150_\(9043-mru\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1150_\(9043-mru\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1112_\(9242-21b\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1112_\(9242-21t\)_firmware:fw1120.00:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1080_\(9080-hex\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1022_\(9105-22a\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1024_\(9105-42a\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1022s_\(9105-22b\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1014_\(9105-41b\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1022_\(9786-22h\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_l1024_\(9786-42h\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1050_\(9043-mrx\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_s1012_\(9028-21b\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1180_\(9080-heu\)_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:ibm:power_system_e1180_\(9080-heu\)_firmware:fw1120.00:*:*:*:*:*:*:*

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