Loading vulnerability…
CVE-2026-42923 is a denial-of-service vulnerability in NLnet Labs Unbound up to and including version 1.25.0. The flaw is in the DNSSEC validator path that consults the negative cache for DS records. That code path does not enforce the NSEC3 hash-calculation limit introduced in Unbound 1.19.1. As a result, when processing DNSSEC-signed data involving NSEC3 records, Unbound can be induced to perform excessive hash computations without the intended bounding logic. An attacker who controls a DNSSEC-signed zone can exploit this by using NSEC3 records with acceptably high iteration counts for child delegations and then causing queries to be resolved by a vulnerable Unbound instance. During this processing, Unbound repeatedly performs the permitted NSEC3 hash calculations in the vulnerable path and holds a global lock protecting the negative cache for the duration of the hashing work, which amplifies the performance impact by blocking other threads that also need negative-cache access.
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
What an attacker gets, and what they’ve been doing with it.
If you can’t patch tonight, do this now.
Patch, then assume compromise.
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
7 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.