Quick answers
- Is CVE-2026-123576 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-123576 being exploited in the wild.
- How severe is CVE-2026-123576?
- High severity, with a CVSS score of 7.5, published 8 November 2026.
- Which products and versions are affected?
- Hickory-Dns Hickory DNS 0.24.0 through 0.26.1.
- Is there a fix for CVE-2026-123576?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-123576 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-123576?
- Check whether you run Hickory-Dns Hickory DNS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The DNS-over-QUIC server pre-allocates buffers upon receiving a length prefix but lacks a timeout mechanism for receiving the complete request body, allowing attackers to hold connections open with only partial data sent. This CWE-770 resource exhaustion vulnerability can be exploited by opening many connections and sending only large length prefixes without completing the requests, exhausting server memory. No timeout is implemented to clean up these incomplete requests.
Affected products
- hickory-dns Hickory DNS 0.24.0 through 0.26.1
Timeline
- 2026-09-03: disclosed: GitHub security advisory GHSA-2f4m-fq7w-mrgx published
- 2026-11-08: advisory