Hickory-DNS 0.26.0 before 0.26.2 DNSSEC Nonexistence Forgery via Wraparound NSEC
Affects hickory-dns 0.26.0 before 0.26.2, specifically the hickory-net crate versions 0.26.0 through 0.26.1. Fixed in 0.26.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.26.2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.26.2.
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.24% · 14th percentile
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The DNSSEC validation in the Hickory DNS hickory-net crate 0.26.0 before 0.26.2 identifies wraparound NSEC records by comparing the next domain name to an SOA record in the response, accepting that SOA even if it fails validation. Attackers who can supply DNS responses can combine a genuine NSEC record and its RRSIG with a crafted SOA record to forge nonexistence of any RRset.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.9/10CVSS 8.9
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
- Would score about 31 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 0.26.2.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- hickory-dns hickory-dns
From 0.26.0 · fixed in 0.26.2
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123587
Is CVE-2026-123587 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A crafted response can combine a genuine NSEC record, its RRSIG, and a crafted SOA record to forge the nonexistence of any RRset. DNSSEC-validated responses can then wrongly report that records do not exist.Source: github.com, vulncheck.com
Which versions are affected by CVE-2026-123587?
hickory-dns: from 0.26.0 before 0.26.2.Source: cve.now feed data
Am I affected, and how do I check?
The advisory lists hickory-dns from 0.26.0 before 0.26.2, and names the hickory-net crate versions 0.26.0 through 0.26.1 as the affected code. To check a project, look at the hickory-net version in its Cargo.lock or Cargo.toml.Source: github.com, vulncheck.com
How do I fix CVE-2026-123587?
Upgrade to hickory-dns 0.26.2, which contains the fix. The facts give no workaround.Source: github.com, vulncheck.com