CVE-2026-42955: Extra fix for CVE-2026-40622 to also clamp the TTL of A/AAAA records disallowing a one-time 'ghost domain' delegation renewal via glue records
CSIRTS triage
- What
- An extra fix for a previous vulnerability restricts TTL of A/AAAA records to prevent ghost domain delegation renewals.
- Who is affected
- Deployments using A/AAAA records in DNS are affected.
- Urgency
- Remediation is low priority due to the low severity of the vulnerability.
- Action
- Monitor for updates and apply them when convenient.
AI-assisted analysis generated from the source advisory — verify against the original.
Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42955
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-2026-429550.20% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 10% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-42955 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
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