RUSTSEC-2026-0540

Source
https://rustsec.org/advisories/RUSTSEC-2026-0540
Import Source
https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0540.json
JSON Data
https://api.osv.dev/v1/vulns/RUSTSEC-2026-0540
Aliases
Published
2026-09-03T12:00:00Z
Modified
2026-11-13T12:55:54Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
Summary
Child-side NSEC or NSEC3 record accepted as proof that a delegation has no DS record
Details

To show that a delegation is insecure, a validator needs proof that the parent zone has no DS record for it. That proof must come from the parent side of the zone cut: RFC 4035 section 5.2, RFC 5155 section 8.9 and RFC 6840 section 4.4 require the matching NSEC or NSEC3 record not to have the SOA bit set, since a record with SOA comes from the child zone's apex.

DNSSEC validation did not check this. An attacker who can answer or modify DNS responses can answer a DS query with the child zone's own signed NSEC or NSEC3 record for its apex, which does not list DS, and have the validator accept that the delegation is insecure. Records in the child zone can then be forged without any signature.

This affects DNSSEC validation through DnssecDnsHandle when built with dnssec-ring or dnssec-aws-lc-rs.

The fix treats a NODATA proof for a DS query as bogus when the directly matching NSEC or NSEC3 record has SOA in its type bitmap. It is in 0.26.2.

Database specific
{
    "license": "CC0-1.0"
}
References

Affected packages

crates.io / hickory-net

Package

Name
hickory-net
View open source insights on deps.dev
Purl
pkg:cargo/hickory-net

Affected ranges

Type
SEMVER
Events
Introduced
0.0.0-0
Fixed
0.26.2

Ecosystem specific

{
    "affected_functions": null,
    "affects": {
        "arch": [],
        "functions": [],
        "os": []
    }
}

Database specific

categories
[
    "privilege-escalation"
]
cvss
"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"
informational
null
source
"https://github.com/rustsec/advisory-db/blob/osv/crates/RUSTSEC-2026-0540.json"