SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-20839

libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.

HIGH 7.5EPSS 3.59%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (3.59%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

libvncclient/sockets.c in LibVNCServer before 0.9.13 has a buffer overflow via a long socket filename.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
3.59% probability · 89th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-120
Affected
libvnc project/libvncserver · canonical/ubuntu linux · debian/debian linux · siemens/simatic itc1500 firmware · siemens/simatic itc1500 pro firmware · siemens/simatic itc1900 firmware · siemens/simatic itc1900 pro firmware · siemens/simatic itc2200 firmware · siemens/simatic itc2200 pro firmware · opensuse/leap
Source
cve@mitre.org
EPSS trend
0%3%5%26 October 2026: 3.59%26 October 202626 October 2026

EPSS 3.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.