With NLnet Labs Unbound up to and including version 1.25.1, applications using libunbound and configured with 'unwanted-reply-threshold', could eventually be abruptly terminated if the threshold is reached and libunbound needs to call 'libworker_alloc_cleanup' since the function is absent from the function call allow list. When an application using libunbound sets 'unwanted-reply-threshold' to any non-zero value and the iterator queries an authoritative that replies with enough wrong-transaction-ID UDP datagrams to cross the threshold, the 'libworker_alloc_cleanup' will eventually be called. Since the function is absent from the function call allow list, this leads to a fatal exit of libunbound and eventual termination of the embedding application.Unbound itself is not affected since its relevant function 'worker_alloc_cleanup' is registed in the allow list and proceeds to perform the documented cache flush.
CVE-2026-44621
Score 5.9 from GitHub Security Advisory published 2026-07-22. a secondary CVSS source baseline 5.9; sources differ by 0.0.
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.9
- EG Score
- 5.9(high)
- EG Risk
- 27(Track)EG Risk 27/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity59% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 17.3%
- KEV
- Not listed
Published
July 22, 2026
Last Modified
July 24, 2026
Advisory Details (1)
Auto-updated Jul 22, 2026Vendor Advisories for CVE-2026-44621(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-44621Microsoft Security Response Center (MSRC)Medium
Libunbound applications configured with 'unwanted-reply-threshold' could eventually be abruptly terminated
- GHSA-3m86-wjgw-cgqcGitHub Security AdvisoriesMedium
With NLnet Labs Unbound up to and including version 1.25.1, applications using libunbound and...
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 9× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-24 14:17 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:15 UTCEG score recompute
- 2026-07-22 22:04 UTCEG score recompute
- 2026-07-22 22:04 UTCGHSA enrichment
- 2026-07-22 15:34 UTCEG score recompute
- 2026-07-22 15:34 UTCGHSA enrichment
- 2026-07-22 13:17 UTCEG score recompute
- 2026-07-22 13:17 UTCMITRE cvelistV5first tracked
Frequently asked(5)
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Dependency Blast Radius
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