How severe is CVE-2020-15863?

CVE-2020-15863 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2020-15863 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-15863?

CVE-2020-15863 primarily affects Qemu. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-15863?

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

When was CVE-2020-15863 published?

CVE-2020-15863 was published on 2020-07-28 and last updated on 2026-06-17.

CVE-2020-15863

CVE-2020-15863 is a medium-severity vulnerability in Qemu with a CVSS 3.x base score of 5.3. 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-787.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.4
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Qemu
Published: 2020-07-28
Last modified: 2026-06-17

Description

hw/net/xgmac.c in the XGMAC Ethernet controller in QEMU before 07-20-2020 has a buffer overflow. This occurs during packet transmission and affects the highbank and midway emulated machines. A guest user or process could use this flaw to crash the QEMU process on the host, resulting in a denial of service or potential privileged code execution. This was fixed in commit 5519724a13664b43e225ca05351c60b4468e4555.

Frequently asked questions

What is CVE-2020-15863?: hw/net/xgmac.c in the XGMAC Ethernet controller in QEMU before 07-20-2020 has a buffer overflow. This occurs during packet transmission and affects the highbank and midway emulated machines. A guest user or process could use this flaw to crash the QEMU process on the host, resulting in a denial of service or potential privileged code execution. This was fixed in commit 5519724a13664b43e225ca05351c60b4468e4555.
How severe is CVE-2020-15863?: CVE-2020-15863 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2020-15863 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-15863?: CVE-2020-15863 primarily affects Qemu. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-15863?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-15863 published?: CVE-2020-15863 was published on 2020-07-28 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*
cpe:2.3:a:qemu:qemu:5.1.0:rc0:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
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:20.04:*:*:*:lts:*:*:*

More vulnerabilities in Qemu

CVE-2022-36648 — Critical (CVSS 10.0): The hardware emulation in the of_dpa_cmd_add_l2_flood of rocker device model in QEMU, as used in 7.0.0 and earlier,…
CVE-2017-16845 — Critical (CVSS 10.0): hw/input/ps2.c in Qemu does not validate 'rptr' and 'count' values during guest migration, leading to out-of-bounds…
CVE-2015-8556 — Critical (CVSS 10.0): Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
CVE-2009-3616 — Critical (CVSS 9.9): Multiple use-after-free vulnerabilities in vnc.c in the VNC server in QEMU 0.10.6 and earlier might allow guest OS…
CVE-2019-12929 — Critical (CVSS 9.8): The QMP guest_exec command in QEMU 4.0.0 and earlier is prone to OS command injection, which allows the attacker to…
CVE-2019-12928 — Critical (CVSS 9.8): The QMP migrate command in QEMU version 4.0.0 and earlier is vulnerable to OS command injection, which allows the…

All CVEs affecting Qemu →

Other CWE-787 (Out-of-bounds Write) vulnerabilities

CVE-2026-42369 — Critical (CVSS 10.0): GV-VMS V20 is a Video Monitoring Software used to gather the feeds of many surveillance cameras and manage other…
CVE-2026-4746 — Critical (CVSS 10.0): Out-of-bounds Write vulnerability in timeplus-io proton (base/poco/Foundation/src‎ modules). This vulnerability is…
CVE-2025-43300 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS…
CVE-2025-24201 — Critical (CVSS 10.0): An out-of-bounds write issue was addressed with improved checks to prevent unauthorized actions. This issue is fixed in…
CVE-2024-42479 — Critical (CVSS 10.0): llama.cpp provides LLM inference in C/C++. The unsafe `data` pointer member in the `rpc_tensor` structure can cause…
CVE-2024-39791 — Critical (CVSS 10.0): Stack-based buffer overflow vulnerabilities affecting Vonets industrial wifi bridge relays and wifi bridge…

Browse all CWE-787 (Out-of-bounds Write) vulnerabilities →