Cyber Resilience

CVE-2026-58050

HighPublic PoC

Published: 28 June 2026

Published
28 June 2026
Modified
30 June 2026
KEV Added
Patch
CVSS Score v4 8.3 CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/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
EPSS Score 0.0033 25.2th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-58050 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Libssh2 Libssh2. Its CVSS base score is 8.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 25.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server…

more

can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow in a connecting libssh2 client.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Integer overflow leads to heap buffer overflow exploitable by malicious SSH server against connecting client, directly enabling client-side code execution.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-7598Same product: Libssh2 Libssh2
CVE-2026-55199Same product: Libssh2 Libssh2
CVE-2026-55200Same product: Libssh2 Libssh2
CVE-2026-58051Same product: Libssh2 Libssh2
CVE-2025-15661Same product: Libssh2 Libssh2
CVE-2025-30405Shared CWE-190
CVE-2026-5732Shared CWE-190
CVE-2025-21338Shared CWE-190
CVE-2025-47392Shared CWE-190
CVE-2026-8949Shared CWE-190

Affected Assets

libssh2
libssh2
≤ 1.11.1

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References