Out-of-bounds read in libssh2
Priority MEDIUM 54CWE-125Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.06275 93rd percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| The libssh2 Project | libssh2 | 1.8.1 | — | No fix listed | CNA |
- libssh2 VendorThe libssh2 Project Affected 1.8.1 Fixed in — No fix listed CNA
CPE configurations NVD · 8
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:* | before 1.8.1 | Vulnerable | The libssh2 Project |
| cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:* | 28 | Vulnerable | Fedoraproject |
| cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:* | 29 | Vulnerable | Fedoraproject |
| cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Debian |
| cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Debian |
| cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:* | 15.0 | Vulnerable | openSUSE |
| cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:* | 42.3 | Vulnerable | openSUSE |
- cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:* Versions before 1.8.1 Vulnerable ·The libssh2 Project
- cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:* Versions 28 Vulnerable ·Fedoraproject
- cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:* Versions 29 Vulnerable ·Fedoraproject
- cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Debian
- cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian
- cpe:2.3:a:netapp:ontap_select_deploy_administration_utility:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:o:opensuse:leap:15.0:*:*:*:*:*:*:* Versions 15.0 Vulnerable ·openSUSE
- cpe:2.3:o:opensuse:leap:42.3:*:*:*:*:*:*:* Versions 42.3 Vulnerable ·openSUSE
Remediation
No fixed version listed by the sources yet.
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
The libssh2 Project libssh2 — openSUSE-SU-2019:1075
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- TI-2019-02868 Out-of-bounds read in libssh2Priority MEDIUM 49
- Advisory ·
The libssh2 Project libssh2 — openSUSE-SU-2019:1109
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- TI-2019-02868 Out-of-bounds read in libssh2Priority MEDIUM 49
Show 3 more groups
- Advisory ·
The libssh2 Project libssh2 — FEDORA-2019-3348cb4934
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- TI-2019-02868 Out-of-bounds read in libssh2Priority MEDIUM 49
- Advisory ·
The libssh2 Project libssh2 — DSA-4431
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- TI-2019-02868 Out-of-bounds read in libssh2Priority MEDIUM 49
- Advisory ·
The libssh2 Project libssh2 — FEDORA-2019-f31c14682f
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- TI-2019-02868 Out-of-bounds read in libssh2Priority MEDIUM 49
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
| Red Hat Virtualization 4 | Affected | No fix planned: Will not fix |
Not affected: 1 product
- Red Hat Enterprise Linux 8 Advanced Virtualization
Timeline
- 2026-10-02 Threatist record created from CVE-2019-3859
- 2026-10-03 Alias added: GHSA-3fjx-35vx-pq97
References
Patch 4
Advisory 13
- https://www.libssh2.org/CVE-2019-3859.html
- FEDORA-2019-f31c14682f
- https://www.broadcom.com/support/fibre-channel-networking/security-advisories/brocade-security-advisory-2019-767
- [debian-lts-announce] 20190326 [SECURITY] [DLA 1730-1] libssh2 security update
- https://security.netapp.com/advisory/ntap-20190327-0005/
- openSUSE-SU-2019:1075
- [debian-lts-announce] 20190402 [SECURITY] [DLA 1730-2] libssh2 regression update
- openSUSE-SU-2019:1109
- FEDORA-2019-3348cb4934
- DSA-4431
- 20190415 [SECURITY] [DSA 4431-1] libssh2 security update
- openSUSE-SU-2019:1290
- openSUSE-SU-2019:1291
More The libssh2 Project Libssh2 vulnerabilities
- TI-2026-39880 libssh2 - Out-of-Bounds Write via Unchecked packet_length in transport.c CVSS 4.0CRITICAL 9.2
- TI-2026-06681 libssh2 userauth.c userauth_password integer overflow CVSS 4.0MEDIUM 6.9
- TI-2023-26623 The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6… CVSS 3.1MEDIUM 5.9
- TI-2026-41806 libssh2 - Free of Uninitialized Pointer in publickey List Cleanup CVSS 4.0HIGH 8.3
- TI-2019-02865 Integer overflow in libssh2 CVSS 3.1HIGH 8.8
- TI-2019-02872 Out-of-bounds read in libssh2 CVSS 3.0CRITICAL 9.1
Sources
- CVE-2019-3859 · CVE Program
- CVE-2019-3859 · NVD
- FIRST EPSS
- GHSA-3fjx-35vx-pq97 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-3859 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences