How severe is CVE-2019-16921?

CVE-2019-16921 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2019-16921 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-16921?

CVE-2019-16921 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2019-16921?

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-2019-16921 published?

CVE-2019-16921 was published on 2019-09-27 and last updated on 2026-06-17.

CVE-2019-16921

CVE-2019-16921 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.5. 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-665.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (78th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-665
Affected product: Linux Linux Kernel
Published: 2019-09-27
Last modified: 2026-06-17

Description

In the Linux kernel before 4.17, hns_roce_alloc_ucontext in drivers/infiniband/hw/hns/hns_roce_main.c does not initialize the resp data structure, which might allow attackers to obtain sensitive information from kernel stack memory, aka CID-df7e40425813.

Frequently asked questions

What is CVE-2019-16921?: In the Linux kernel before 4.17, hns_roce_alloc_ucontext in drivers/infiniband/hw/hns/hns_roce_main.c does not initialize the resp data structure, which might allow attackers to obtain sensitive information from kernel stack memory, aka CID-df7e40425813.
How severe is CVE-2019-16921?: CVE-2019-16921 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2019-16921 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (78th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-16921?: CVE-2019-16921 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2019-16921?: 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-2019-16921 published?: CVE-2019-16921 was published on 2019-09-27 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

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