CVE-2026-55973
CVE-2026-55973: 1 tracked advisory record across Red Hat. Compare source-reported impact, fixes and remediation.
Compare the source-linked records below. Ratings and product/version details belong to each advisory; they are not a single CVE-wide score or proof that every listed product is affected. How VulniPulse collects and checks evidence.
Vendor advisory comparison
Red Hat
1 advisory- Advisory severityHigh7.5
High [CVE-2026-55973] Denial of Service via malformed EDNS Report-Channel option
CVE-2026-55973Source published Source updated
In NLnet Labs Unbound 1.23.0 up to and including 1.25.1, when 'dns-error-reporting: yes' is set, the EDNS Report-Channel option (code 18) from the last upstream response is read and uses the option's length as the length of the agent domain. When a domain name check is performed on the agent domain, the returned lenght is not used and if the agent domain is followed by garbage, those bytes are moved onto the tail of the synthetic '_er.' report query name. That query name is later used in the iterator via a subquery to send out the DNS Error Report and when Unbound tries to walk that query name during 'find_closest_of_type()', it strips labels using the query name length rather than stopping at the embedded root, walks one byte past it, and feeds the first garbage byte to…
- Affected products in this advisory
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4.22
- Red Hat Hardened Images
1 more entries in the full advisory.
- Source-reported affected versions
- 1.23.0
- 1.25.1
- Source-reported fixed versions
- unbound-0:1.24.2-7.el10_2.4
- unbound-0:1.24.2-3.el9_8.4
- rhcos-4.22.9.8.202608251819-0
- unbound-main-1.25.2-0.1.hum1
4 more entries in the full advisory.
- Mitigation guidance
- No mitigation guidance extracted; consult the source.
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