How severe is CVE-2020-14399?

CVE-2020-14399 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 none, integrity none, and availability high.

Is CVE-2020-14399 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-14399?

CVE-2020-14399 primarily affects Libvncserver Project Libvncserver. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-14399?

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-2020-14399 published?

CVE-2020-14399 was published on 2020-06-17 and last updated on 2026-06-17.

CVE-2020-14399

CVE-2020-14399 is a high-severity vulnerability in Libvncserver Project Libvncserver 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.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 3% (85th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Libvncserver Project Libvncserver
Published: 2020-06-17
Last modified: 2026-06-17

Description

An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed through uint32_t pointers in libvncclient/rfbproto.c. NOTE: there is reportedly "no trust boundary crossed.

Frequently asked questions

What is CVE-2020-14399?: An issue was discovered in LibVNCServer before 0.9.13. Byte-aligned data is accessed through uint32_t pointers in libvncclient/rfbproto.c. NOTE: there is reportedly "no trust boundary crossed.
How severe is CVE-2020-14399?: CVE-2020-14399 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 none, integrity none, and availability high.
Is CVE-2020-14399 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (85th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-14399?: CVE-2020-14399 primarily affects Libvncserver Project Libvncserver. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-14399?: 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-2020-14399 published?: CVE-2020-14399 was published on 2020-06-17 and last updated on 2026-06-17.

References

Affected products (8)

cpe:2.3:a:libvncserver_project:libvncserver:*:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
cpe:2.3:o:opensuse:leap:15.2:*:*:*:*:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*

More vulnerabilities in Libvncserver Project Libvncserver

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CVE-2016-9941 — Critical (CVSS 9.8): Heap-based buffer overflow in rfbproto.c in LibVNCClient in LibVNCServer before 0.9.11 allows remote servers to cause a…
CVE-2026-32853 — High (CVSS 8.1): LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in…
CVE-2026-32854 — High (CVSS 7.5): LibVNCServer versions 0.9.15 and prior (fixed in commit dc78dee) contain null pointer dereference vulnerabilities in…

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