CVE & CISA-KEV Catalog

CVE-2019-3863

HIGHEPSS 88th pctl
7.5
CVSS v3
NVD

Description

A flaw was found in libssh2 before 1.8.1 creating a vulnerability on the SSH client side. A server could send a multiple keyboard interactive response messages whose total length are greater than unsigned char max characters. This value is used by the SSH client as an index to copy memory causing in an out of bounds memory write error.

How to fix

Remediation Available
libssh2Debian
Fixed in:1.8.0-2.1CVE-2019-3863
Fixed in:1.8.0-2.1CVE-2019-3863
Fixed in:1.8.0-2.1CVE-2019-3863
Fixed in:1.8.0-2.1CVE-2019-3863
libssh2Ubuntu
Fixed in:1.5.0-2ubuntu0.1+esm1USN-5308-1
libssh2-1Ubuntu
Fixed in:1.5.0-2ubuntu0.1+esm1USN-5308-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Exploit Intelligence

3.44%probability of exploitation in 30 days
88thpercentile

Elevated risk: more likely to be exploited than 88% of all known CVEs.

References

Related Vulnerabilities

Other CWE-190 (Integer Overflow) vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2020-16040Medium6.5100%-Fix
CVE-2019-11477High7.599%-Fix
CVE-2023-44443High7.894%-Fix
CVE-2014-0569High9.390%--
CVE-2017-3599High7.590%-Fix
CVE-2023-21716Critical9.882%-Fix
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-12-19.