CVE-2026-27831
CVE-2026-27831 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (34th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-8787
- Weakness: CWE-125
- Published:
- Last modified:
Description
rldns is an open source DNS server. Version 1.3 has a heap-based out-of-bounds read that leads to denial of service. Version 1.4 contains a patch for the issue.
Frequently asked questions
- What is CVE-2026-27831?
- rldns is an open source DNS server. Version 1.3 has a heap-based out-of-bounds read that leads to denial of service. Version 1.4 contains a patch for the issue.
- How severe is CVE-2026-27831?
- CVE-2026-27831 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2026-27831 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-27831?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2026-27831 have an EU (EUVD) identifier?
- Yes. CVE-2026-27831 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8787.
- When was CVE-2026-27831 published?
- CVE-2026-27831 was published on 2026-02-26 and last updated on 2026-06-17.
References
- https://github.com/bluedragonsecurity/rldns-1.3-heap-out-of-bounds-vulnerability-fixed-in-rldns-1.4
- https://github.com/bluedragonsecurity/rldns/security/advisories/GHSA-fv38-45j4-g9x4
- https://github.com/bluedragonsecurity/rldns_archives/blob/main/diff/rldns-1.4.diff
- https://medium.com/@w1sdom/heap-based-buffer-over-read-vulnerability-in-rldns-1-3-5da3bccdc031
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