Integer overflow in libssh2
Priority MEDIUM 49CWE-190Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 33 fixed, 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.
Summary
An integer overflow flaw which could lead to an out of bounds write was discovered in libssh2 before 1.8.1 in the way SSH_MSG_CHANNEL_REQUEST packets with an exit signal are parsed. A remote attacker who compromises a SSH server may be able to execute code on the client system when a user connects to the server.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.06131 93rd percentileScored 2026-11-07
Fix Partial Red Hat: 6 advisoriesRed Hat: 33 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
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 · 16
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:* | 1.2.8 – 1.8.0 | Vulnerable | The libssh2 Project |
| 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:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:* | 7.6 | Vulnerable | Red Hat |
- cpe:2.3:a:libssh2:libssh2:*:*:*:*:*:*:*:* Versions 1.2.8 – 1.8.0 Vulnerable ·The libssh2 Project
- 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
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:advanced_virtualization:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_aus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
Show 6 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:* | 7.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:* | 7.6 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:* | 28 | Vulnerable | Fedoraproject |
| cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.56:*:*:*:*:*:*:* | 8.56 | Vulnerable | Oracle |
| cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:*:*:*:*:*:*:* | 8.57 | Vulnerable | Oracle |
- cpe:2.3:o:redhat:enterprise_linux_server_eus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server_tus:7.6:*:*:*:*:*:*:* Versions 7.6 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:28:*:*:*:*:*:*:* Versions 28 Vulnerable ·Fedoraproject
- cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.56:*:*:*:*:*:*:* Versions 8.56 Vulnerable ·Oracle
- cpe:2.3:a:oracle:peoplesoft_enterprise_peopletools:8.57:*:*:*:*:*:*:* Versions 8.57 Vulnerable ·Oracle
Remediation
Red Hat 6 advisories
- RHSA-2019:2399 Released 2019-08-07 · Red Hat rating Importantlibssh2 security update
- Red Hat Enterprise Linux Server AUS (v. 7.3) libssh2-1.4.3-11.el7_3.1
- Red Hat Enterprise Linux Server E4S (v. 7.3) libssh2-1.4.3-11.el7_3.1
- Red Hat Enterprise Linux Server Optional AUS (v. 7.3) libssh2-devel-1.4.3-11.el7_3.1, libssh2-docs-1.4.3-11.el7_3.1
- Red Hat Enterprise Linux Server Optional E4S (v. 7.3) libssh2-devel-1.4.3-11.el7_3.1, libssh2-docs-1.4.3-11.el7_3.1
- Red Hat Enterprise Linux Server Optional TUS (v. 7.3) libssh2-devel-1.4.3-11.el7_3.1, libssh2-docs-1.4.3-11.el7_3.1
- Red Hat Enterprise Linux Server TUS (v. 7.3) libssh2-1.4.3-11.el7_3.1
- RHSA-2019:1943 Released 2019-07-30 · Red Hat rating Importantlibssh2 security update
- Red Hat Enterprise Linux ComputeNode EUS (v. 7.4) libssh2-1.4.3-11.el7_4.1
- Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.4) libssh2-devel-1.4.3-11.el7_4.1, libssh2-docs-1.4.3-11.el7_4.1
- Red Hat Enterprise Linux Server EUS (v. 7.4) libssh2-1.4.3-11.el7_4.1, libssh2-1.4.3-11.el7_4.1.ppc
- Red Hat Enterprise Linux Server Optional EUS (v. 7.4) libssh2-devel-1.4.3-11.el7_4.1, libssh2-devel-1.4.3-11.el7_4.1.ppc, libssh2-docs-1.4.3-11.el7_4.1
- RHSA-2019:1791 Released 2019-07-16 · Red Hat rating Importantlibssh2 security update
- Red Hat Enterprise Linux ComputeNode EUS (v. 7.5) libssh2-1.4.3-11.el7_5.1
- Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.5) libssh2-devel-1.4.3-11.el7_5.1, libssh2-docs-1.4.3-11.el7_5.1
- Red Hat Enterprise Linux Server EUS (v. 7.5) libssh2-1.4.3-11.el7_5.1, libssh2-1.4.3-11.el7_5.1.ppc
- Red Hat Enterprise Linux Server Optional EUS (v. 7.5) libssh2-devel-1.4.3-11.el7_5.1, libssh2-devel-1.4.3-11.el7_5.1.ppc, libssh2-docs-1.4.3-11.el7_5.1
Show 3 more Red Hat advisories
- RHSA-2019:1652 Released 2019-07-02 · Red Hat rating Importantlibssh2 security update
- Red Hat Enterprise Linux Desktop (v. 6) libssh2-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux Desktop Optional (v. 6) libssh2-devel-1.4.2-3.el6_10.1, libssh2-docs-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux HPC Node (v. 6) libssh2-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux HPC Node Optional (v. 6) libssh2-devel-1.4.2-3.el6_10.1, libssh2-docs-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux Server (v. 6) libssh2-1.4.2-3.el6_10.1, libssh2-1.4.2-3.el6_10.1.ppc
- Red Hat Enterprise Linux Server Optional (v. 6) libssh2-devel-1.4.2-3.el6_10.1, libssh2-devel-1.4.2-3.el6_10.1.ppc, libssh2-docs-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux Workstation (v. 6) libssh2-1.4.2-3.el6_10.1
- Red Hat Enterprise Linux Workstation Optional (v. 6) libssh2-devel-1.4.2-3.el6_10.1, libssh2-docs-1.4.2-3.el6_10.1
- RHSA-2019:1175 Released 2019-05-14 · Red Hat rating Importantvirt:rhel security update
- Red Hat Enterprise Linux AppStream (v. 8) SLOF-20171214-5.gitfa98132.module+el8.0.0+3075+09be6b65.noarch::virt:rhel, SLOF-20171214-5.gitfa98132.module+el8.0.0+3075+09be6b65.src::virt:rhel, hivex-1.3.15-6.module+el8.0.0+3075+09be6b65.aarch64::virt:rhel +47
- RHSA-2019:0679 Released 2019-03-28 · Red Hat rating Importantlibssh2 security update
- Red Hat Enterprise Linux Client (v. 7) libssh2-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux Client Optional (v. 7) libssh2-devel-1.4.3-12.el7_6.2, libssh2-docs-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux ComputeNode (v. 7) libssh2-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux ComputeNode Optional (v. 7) libssh2-devel-1.4.3-12.el7_6.2, libssh2-docs-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux Server (v. 7) libssh2-1.4.3-12.el7_6.2, libssh2-1.4.3-12.el7_6.2.ppc
- Red Hat Enterprise Linux Server Optional (v. 7) libssh2-devel-1.4.3-12.el7_6.2, libssh2-devel-1.4.3-12.el7_6.2.ppc, libssh2-docs-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux Workstation (v. 7) libssh2-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux Workstation Optional (v. 7) libssh2-devel-1.4.3-12.el7_6.2, libssh2-docs-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) libssh2-1.4.3-12.el7_6.2
- Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) libssh2-devel-1.4.3-12.el7_6.2, libssh2-docs-1.4.3-12.el7_6.2
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-2019-02869 Out-of-bounds read in libssh2Priority MEDIUM 54
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- Advisory ·
The libssh2 Project libssh2 — openSUSE-SU-2019:1109
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02869 Out-of-bounds read in libssh2Priority MEDIUM 54
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
Show 8 more groups
- Advisory ·
The libssh2 Project libssh2 — FEDORA-2019-3348cb4934
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02869 Out-of-bounds read in libssh2Priority MEDIUM 54
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- Advisory ·
The libssh2 Project libssh2 — DSA-4431
9 records Highest priority Priority MEDIUM 9 MEDIUM
Other records, highest priority first
- TI-2019-02869 Out-of-bounds read in libssh2Priority MEDIUM 54
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02872 Out-of-bounds read in libssh2Priority MEDIUM 50
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:0679
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:1175
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:1652
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:1791
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:1943
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
- Advisory ·
The libssh2 Project libssh2 — RHSA-2019:2399
4 records Highest priority Priority MEDIUM 4 MEDIUM
Other records, highest priority first
- TI-2019-02865 Integer overflow in libssh2Priority MEDIUM 52
- TI-2019-02866 Integer overflow in libssh2Priority MEDIUM 49
- TI-2019-02873 Integer overflow in libssh2Priority MEDIUM 46
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 8 Advanced Virtualization | Affected | No fix yet |
| Red Hat Virtualization 4 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2019:1175 |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux Client Optional (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux ComputeNode (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux ComputeNode EUS (v. 7.4) | Fixed | RHSA-2019:1943 |
| Red Hat Enterprise Linux ComputeNode EUS (v. 7.5) | Fixed | RHSA-2019:1791 |
| Red Hat Enterprise Linux ComputeNode Optional (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.4) | Fixed | RHSA-2019:1943 |
| Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.5) | Fixed | RHSA-2019:1791 |
| Red Hat Enterprise Linux Desktop (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Desktop Optional (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux HPC Node (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux HPC Node Optional (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Server (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux Server AUS (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Server E4S (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Server EUS (v. 7.4) | Fixed | RHSA-2019:1943 |
| Red Hat Enterprise Linux Server EUS (v. 7.5) | Fixed | RHSA-2019:1791 |
| Red Hat Enterprise Linux Server Optional (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Server Optional (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux Server Optional AUS (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Server Optional E4S (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Server Optional EUS (v. 7.4) | Fixed | RHSA-2019:1943 |
| Red Hat Enterprise Linux Server Optional EUS (v. 7.5) | Fixed | RHSA-2019:1791 |
| Red Hat Enterprise Linux Server Optional TUS (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Server TUS (v. 7.3) | Fixed | RHSA-2019:2399 |
| Red Hat Enterprise Linux Workstation (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux Workstation Optional (v. 6) | Fixed | RHSA-2019:1652 |
| Red Hat Enterprise Linux Workstation Optional (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) | Fixed | RHSA-2019:0679 |
| Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) | Fixed | RHSA-2019:0679 |
Timeline
- 2026-10-02 Threatist record created from CVE-2019-3857
- 2026-10-03 Alias added: GHSA-mq4f-qjqv-2ff5
References
Patch 3
Advisory 13
- [debian-lts-announce] 20190326 [SECURITY] [DLA 1730-1] libssh2 security update
- https://security.netapp.com/advisory/ntap-20190327-0005/
- RHSA-2019:0679
- openSUSE-SU-2019:1075
- openSUSE-SU-2019:1109
- FEDORA-2019-3348cb4934
- DSA-4431
- 20190415 [SECURITY] [DSA 4431-1] libssh2 security update
- RHSA-2019:1175
- RHSA-2019:1652
- RHSA-2019:1791
- RHSA-2019:1943
- RHSA-2019:2399
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-2019-02869 Out-of-bounds read in libssh2 CVSS 3.1CRITICAL 9.1
- TI-2019-02865 Integer overflow in libssh2 CVSS 3.1HIGH 8.8
Sources
- CVE-2019-3857 · CVE Program
- CVE-2019-3857 · NVD
- FIRST EPSS
- GHSA-mq4f-qjqv-2ff5 · GitHub Advisory Database · CC BY 4.0
- CVE-2019-3857 · Red Hat security data · CC BY 4.0
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