CVE-2026-58227: TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain
CSIRTS triage
- What
- TLS/DTLS implementation allows unbounded recursion during processing of cross-signed peer certificate chains, enabling denial of service.
- Who is affected
- Systems using TLS/DTLS implementations with certificate chain validation enabled.
- Urgency
- Severity unknown but DoS potential present; clarify affected libraries and patch availability.
- Action
- Identify affected TLS/DTLS library versions and apply patches or disable cross-signed chain processing.
AI-assisted analysis generated from the source advisory — verify against the original.
Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58227
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-2026-582270.39% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 32% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-58227 | coverage & exploitation status | NVD · CVE.org |
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