Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/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:XSummary
CVE-2026-7598 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Libssh2 Libssh2. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 38th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-7598 is an integer overflow vulnerability in libssh2 versions up to and including 1.11.1. The issue resides in the userauth_password function within the src/userauth.c file, where manipulation of the username_len or password_len arguments can trigger the overflow. This flaw, associated with CWE-189 (Numeric Errors) and CWE-190 (Integer Overflow or Wraparound), carries a CVSS v3.1 base score of 7.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L), rated as High severity.
Remote attackers can exploit this vulnerability over the network without authentication or user interaction. By crafting malicious inputs for username_len or password_len during SSH authentication attempts, an attacker could cause the integer overflow, potentially leading to limited impacts on confidentiality, integrity, and availability, such as partial data exposure, modification, or denial of service in affected libssh2-dependent applications.
Mitigation requires applying the patch from commit 256d04b60d80bf1190e96b0ad1e91b2174d744b1, available via the libssh2 GitHub repository and pull request #1858. Security practitioners should upgrade to a patched version of libssh2 beyond 1.11.1 and review integrated applications for exposure during password-based authentication flows. Additional details are documented on VulDB entries for submission 805564 and vulnerability 360555.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-26722
Vulnerability Data
A security vulnerability has been detected in libssh2 up to 1.11.1. The impacted element is the function userauth_password of the file src/userauth.c. Such manipulation of the argument username_len/password_len leads to integer overflow. The attack may be launched remotely. The name…
more
of the patch is 256d04b60d80bf1190e96b0ad1e91b2174d744b1. A patch should be applied to remediate this issue.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.