CVE-2026-27623: Valkey has Pre-Authentication DOS from malformed RESP request
CSIRTS triage
- What
- Malformed RESP requests can trigger a pre-authentication denial of service condition.
- Who is affected
- All Valkey deployments are affected regardless of authentication configuration.
- Urgency
- High; DOS vulnerability affecting availability with CVSS 7.5, though not yet exploited.
- Action
- Upgrade Valkey to a patched version that validates RESP request format before processing.
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-2026-27623
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-2026-276230.35% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 28% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-27623 | coverage & exploitation status | NVD · CVE.org |
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