Libssh: libssh: stack buffer overflow in sftp server longname construction
Priority LOW 33CWE-121Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-121 and the CVSS impact.
Summary
A flaw was found in libssh. During SFTP server directory listing, the longname field is constructed with unsafe concatenation into a fixed-size stack buffer. When a client causes the server to list attacker-controlled filenames, sufficiently long names can overflow that stack buffer and may lead to crashes or possible code execution on the server.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00168 6th percentileScored 2026-11-07
Fix Fixed Red Hat: 2 advisories
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 |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | 0.12.0-3.el10_2 | Patch available | CNA |
| Red Hat | Red Hat Hardened Images | — | 0.12.2-1.hum1 | Patch available | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | Not affected | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | Not affected | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 0.12.0-3.el10_2 Patch available CNA
- Red Hat Hardened Images VendorRed Hat Affected — Fixed in 0.12.2-1.hum1 Patch available CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — Not affected CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — Not affected CNA
CPE configurations NVD · 20
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* | 0.11.0 to before 0.11.5 | Vulnerable | libssh |
| cpe:2.3:a:libssh:libssh:0.12.0:*:*:*:*:*:*:* | 0.12.0 | Vulnerable | libssh |
| cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:arm64:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:x64:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:arm64:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:x64:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:arm64:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:x64:* | 10.2 | Vulnerable | Red Hat |
- cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:* Versions 0.11.0 to before 0.11.5 Vulnerable ·libssh
- cpe:2.3:a:libssh:libssh:0.12.0:*:*:*:*:*:*:* Versions 0.12.0 Vulnerable ·libssh
- cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:arm64:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:x64:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:arm64:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.2:*:*:*:*:*:x64:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:arm64:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_els:10.2:*:*:*:*:*:x64:* Versions 10.2 Vulnerable ·Red Hat
Show 10 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:arm64:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:x64:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:10.2:*:*:*:*:*:*:* | 10.2 | Vulnerable | Red Hat |
- cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:arm64:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_eus:10.2:*:*:*:*:*:x64:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_els:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_els:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:10.2:*:*:*:*:*:*:* Versions 10.2 Vulnerable ·Red Hat
Remediation
Red Hat 2 advisories
- RHSA-2026:55855 Released 2026-08-17 · Red Hat rating Importantlibssh security update
- Red Hat Enterprise Linux AppStream (v. 10) libssh-devel-0.12.0-3.el10_2
- Red Hat Enterprise Linux BaseOS (v. 10) libssh-0.12.0-3.el10_2, libssh-config-0.12.0-3.el10_2
- RHSA-2026:47768 Released 2026-07-29 · Red Hat rating ModerateRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images libssh-0.12.2-1.hum1@aarch64, libssh-0.12.2-1.hum1@src, libssh-0.12.2-1.hum1@x86_64 +4
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 and 2 more products — RHSA-2026:55855
11 records Highest priority Priority MEDIUM 1 MEDIUM, 10 LOW
Other records, highest priority first
- TI-2026-42667 Libssh: libssh: authentication bypass via missing gssapi principal checkPriority MEDIUM 41
- TI-2026-42663 Libssh: libssh: integrity downgrade via openssl aes-gcm tag verificationPriority LOW 39
- TI-2026-42666 Libssh: libssh: use-after-free via data callbacks on closed channelsPriority LOW 33
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:55855 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:55855 |
| Red Hat Hardened Images | Fixed | RHSA-2026:47768 |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-15370
- 2026-10-03 Alias added: GHSA-6j7f-8jjp-mm8c
References
More Red Hat Enterprise Linux vulnerabilities
- TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
- TI-2018-10530 Code injection in [UNKNOWN] RichFaces KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05975 GNU Bash through 4.3 bash43-025 processes trailing strings after certain malformed… KEVCVSS 3.1CRITICAL 9.8
- TI-2014-05157 GNU Bash through 4.3 processes trailing strings after function definitions in the values… KEVCVSS 3.1CRITICAL 9.8
- TI-2025-23530 Sudo before 1.9.17p1 allows local users to obtain root access because /etc/nsswitch.conf… KEVCVSS 3.1CRITICAL 9.3
- TI-2021-17490 mod_proxy SSRF KEVCVSS 3.1CRITICAL 9.0
Sources
- CVE-2026-15370 · CVE Program
- CVE-2026-15370 · NVD
- FIRST EPSS
- GHSA-6j7f-8jjp-mm8c · GitHub Advisory Database · CC BY 4.0
- CVE-2026-15370 · 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