CVE-2026-58317
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term...
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- Active
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.
- Record
CVE-2026-58317- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N - CVSS 3.0
- 6.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-196
- Updated
- 2026-11-02
EUVDEUVD-2026-45140
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.
- Record
EUVD-2026-45140- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-mmcg-pw3p-cwjh
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term...
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.
- Record
GHSA-mmcg-pw3p-cwjh- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.0
- 6.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-196
- Updated
- 2026-11-02
NVD
Unsigned to Signed Conversion Error (CWE-196) vulnerability exists in TTSSH2 plugin of Tera Term provided by TeraTerm Project. When Tera Term attempts to establish an SSH connection to a server set up by an attacker, out-of-bounds read/write may occur. As a result, the contents of adjacent memory regions may be transmitted to the server, and Tera Term may behave unexpected or terminate abnormally.
- Record
CVE-2026-58317- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.0
- 6.3 Medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L - Weakness
- CWE-196
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-58317 is a medium vulnerability (CVSS 5.1) in Teraterm Project Ttssh2, published July 17, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.32%, the 25th percentile. No source names a fixed version.