Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2019-3859

CVE-2019-3859CRITICAL

The libssh2 Project libssh2 — An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions.

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  N  H    9.1   .0628   93.5     —

AFFECTED
  Product  Versions  Fixed
  libssh2  1.8.1 –   —

TIMELINE
  Jan 3   Reserved by redhat
  Mar 20  Published (CNA: redhat)
  Oct 14  RESCORED — CVE-2019-3859 (The libssh2 Project libssh2). CVSS 5 → 9.1 (NVD).

CWE-125 · CNA: redhat · CVSS v3.1 · 21 references · NVD status: Modified

Description

An out of bounds read flaw was discovered in libssh2 before 1.8.1 in the _libssh2_packet_require and _libssh2_packet_requirev functions. A remote attacker who compromises a SSH server may be able to cause a Denial of Service or read data in the client memory.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
January 3, 2019	Reserved	Reserved by redhat
March 20, 2019	Published	Published (CNA: redhat)
October 14, 2026	RESCORED	RESCORED — CVE-2019-3859 (The libssh2 Project libssh2). CVSS 5 → 9.1 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
The libssh2 Project	libssh2	—	1.8.1	—

Weaknesses

CWE-125

References (21)

http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00040.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00003.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00102.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00103.html [Mailing List, Third Party Advisory]
http://packetstormsecurity.com/files/152136/Slackware-Security-Advisory-libssh2-Updates.html [Patch, Third Party Advisory, VDB Entry]
http://www.openwall.com/lists/oss-security/2019/03/18/3 [Mailing List, Patch, Third Party Advisory]
http://www.securityfocus.com/bid/107485 [Third Party Advisory, VDB Entry]
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3859 [Issue Tracking, Patch, Third Party Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://lists.debian.org/debian-lts-announce/2019/03/msg00032.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2019/04/msg00006.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2019/07/msg00024.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5DK6VO2CEUTAJFYIKWNZKEKYMYR3NO2O/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XCWEA5ZCLKRDUK62QVVYMFWLWKOPX3LO/
https://seclists.org/bugtraq/2019/Apr/25 [Mailing List, Third Party Advisory]
https://seclists.org/bugtraq/2019/Mar/25 [Mailing List, Patch, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20190327-0005/ [Third Party Advisory]
https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767 [Third Party Advisory]
https://www.debian.org/security/2019/dsa-4431 [Third Party Advisory]
https://www.libssh2.org/CVE-2019-3859.html [Vendor Advisory]
https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html

Authoritative record: CVE-2019-3859 at cve.org

Vendors: the libssh2 project

Weaknesses: CWE-125

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2019-3859 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.