CVE-2019-3859

31

FAUCET Score

CVE-2019-3859 is an out-of-bounds read vulnerability in libssh2 versions prior to 1.8.1, specifically within the _libssh2_packet_require and _libssh2_packet_requirev functions. This flaw affects various products including Debian, Fedora, NetApp, and OpenSUSE. It carries a critical CVSS score of 9.1, indicating a high impact with potential for remote attackers to cause Denial of Service or read sensitive client memory without requiring authentication or user interaction. While there is no evidence of active exploitation (KEV: No) and no public exploit code (Metasploit, Nuclei, ExploitDB: None), the vulnerability has garnered significant community discussion with 11 mentions and some media coverage.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		< 1.8.1CPE matchmatch criteria	cpe:2.3:a:libssh2:libssh2::::::::
		28CPE matchmatch criteria	cpe:2.3:o:fedoraproject:fedora:28:::::::*
		29CPE matchmatch criteria	cpe:2.3:o:fedoraproject:fedora:29:::::::*
		8.0CPE matchmatch criteria	cpe:2.3:o:debian:debian_linux:8.0:::::::*
		9.0CPE matchmatch criteria	cpe:2.3:o:debian:debian_linux:9.0:::::::*

CVSS Data

CVSS version used by this source: 3.0

5.0MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

LOW

Exploitability Score

1.6

Impact Score

3.4

CvssVersion

3.0

Exploit Intelligence

EPSS Score

6.28%

Probability of exploitation in next 30 days

EPSS Percentile

92.8%

Percentile rank of EPSS score among Peer Group

As of 2026-07-27

Model: v2026.06.15

This CVE's current EPSS score of 0.0628 is in the 87th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (6)

redhatpatch availablevia nvd_reference

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 6Fixed in: libssh2

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 7Fixed in: libssh2

redhatend of lifevia redhat_api

Product: Red Hat Enterprise Linux 8Fixed in: virt:rhel/libssh2

redhatend of lifevia redhat_api

Product: Red Hat Virtualization 4Fixed in: redhat-virtualization-host

redhatend of lifevia redhat_api

Product: Red Hat Virtualization 4Fixed in: rhvm-appliance

Vendor Advisories (1)

redhatCVE-2019-3859Moderate

libssh2: Unchecked use of _libssh2_packet_require and _libssh2_packet_requirev resulting in out-of-bounds read

References

lists.opensuse.org / opensuse-security-announce/2019-03/msg00040.html

Mailing ListThird Party Advisory

lists.opensuse.org / opensuse-security-announce/2019-04/msg00003.html

Mailing ListThird Party Advisory

lists.opensuse.org / opensuse-security-announce/2019-04/msg00102.html

Mailing ListThird Party Advisory

lists.opensuse.org / opensuse-security-announce/2019-04/msg00103.html

Mailing ListThird Party Advisory

packetstormsecurity.com / files/152136/Slackware-Security-Advisory-libssh2-Updates.html

PatchThird Party AdvisoryVDB Entry

bugzilla.redhat.com / show_bug.cgi

Issue TrackingPatchThird Party Advisory

lists.debian.org / debian-lts-announce/2019/03/msg00032.html

Mailing ListThird Party Advisory

lists.debian.org / debian-lts-announce/2019/04/msg00006.html

Mailing ListThird Party Advisory

lists.debian.org / debian-lts-announce/2019/07/msg00024.html

lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O

lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/XCWEA5ZCLKRDUK62QVVYMFWLWKOPX3LO

seclists.org / bugtraq/2019/Apr/25

Mailing ListThird Party Advisory

seclists.org / bugtraq/2019/Mar/25

Mailing ListPatchThird Party Advisory

security.netapp.com / advisory/ntap-20190327-0005

Third Party Advisory

broadcom.com / support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767

Third Party Advisory

debian.org / security/2019/dsa-4431

Third Party Advisory

libssh2.org / CVE-2019-3859.html

Vendor Advisory

oracle.com / technetwork/security-advisory/cpuoct2019-5072832.html

openwall.com / lists/oss-security/2019/03/18/3

Mailing ListPatchThird Party Advisory

securityfocus.com / bid/107485

Third Party AdvisoryVDB Entry