CVE-2026-66034: libssh2 Heap Out-of-Bounds Read via publickey subsystem
CSIRTS triage
- What
- A heap out-of-bounds read vulnerability exists via the publickey subsystem.
- Who is affected
- Deployments using libssh2 are affected.
- Urgency
- Remediation is urgent due to high severity (CVSS 7.5) and potential for exploitation.
- Action
- Update to the patched version of libssh2.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66034
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-660340.25% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 17% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-66034 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
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