How severe is CVE-2018-20124?

CVE-2018-20124 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2018-20124 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-20124?

CVE-2018-20124 primarily affects Qemu. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-20124?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2018-20124 published?

CVE-2018-20124 was published on 2018-12-20 and last updated on 2026-06-17.

CVE-2018-20124

CVE-2018-20124 is a medium-severity vulnerability in Qemu with a CVSS 3.x base score of 5.5. 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-125.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v2: 2.1
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-125
Affected product: Qemu
Published: 2018-12-20
Last modified: 2026-06-17

Description

hw/rdma/rdma_backend.c in QEMU allows guest OS users to trigger out-of-bounds access via a PvrdmaSqWqe ring element with a large num_sge value.

Frequently asked questions

What is CVE-2018-20124?: hw/rdma/rdma_backend.c in QEMU allows guest OS users to trigger out-of-bounds access via a PvrdmaSqWqe ring element with a large num_sge value.
How severe is CVE-2018-20124?: CVE-2018-20124 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2018-20124 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-20124?: CVE-2018-20124 primarily affects Qemu. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-20124?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2018-20124 published?: CVE-2018-20124 was published on 2018-12-20 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*

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