CVSS 4.0
8.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NCVE-2026-123604 Hickory DNS 0.26.0-beta.1 before 0.26.2 Resource Exhaustion DoS via NameServerPool::try_send TC-Retry Loop
High (8.7) in hickory-dns hickory-dns. EPSS 0.3% estimated probability of exploitation activity in the next 30 days. Fixed in hickory-resolver 0.26.2.
On this page
Hickory DNS hickory-resolver 0.26.0-beta.1 before 0.26.2 contains an unbounded retry loop in NameServerPool::try_send, which re-queues truncated (TC) responses without checking the answering transport or counting iterations. A malicious authoritative server returning TC=1 on every transport keeps the resolver spinning on a persistent TCP connection until the 5-second request deadline expires, causing resource exhaustion.
Severity
CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- EPSS
- 0.3% estimated probability of exploitation activity in the next 30 days; 28th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: none · Automatable: yes · Technical impact: partial, assessed 2026-11-12. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-835 Loop with Unreachable Exit Condition (Infinite Loop)
- Published
- Modified
- Assigned by
- VulnCheck (CNA)
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| hickory-dns | from 0.26.0-beta.1 before 0.26.2 |
Fix and patched versions
hickory-resolver(crates.io): fixed in 0.26.2- Debian: fixed package versions per release
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-6w6g-hm98-mhgm | crates.io | hickory-resolver | >=0.26.0-beta.1 <0.26.2 | 0.26.2 |
| RUSTSEC-2026-0513 | crates.io | hickory-resolver | >=0.26.0-beta.1 <0.26.2 | 0.26.2 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Debian | 13 | rust-hickory-resolver | no fix listed | DEBIAN-CVE-2026-123604 |
| Debian | 14 | rust-hickory-resolver | 0.26.3-1 | DEBIAN-CVE-2026-123604 |
| Ubuntu | 24.04:LTS, 26.04:LTS, 26.10 | rust-hickory-resolver | no fix listed | UBUNTU-CVE-2026-123604 |
From the distributions' data via OSV.dev: the Debian Security Tracker; Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Debian · Ubuntu.
History
- The NVD deferred its analysis
Changes since this site first stored the record. The same for every record: /api/public/changes.