SB2026100159 - openEuler 22.03 LTS SP4 update for coredns
Published: October 1, 2026 Updated: October 1, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2026-82399)
CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to allocation of resources without limits or throttling in custom DNS request transport handlers when parsing crafted DNS messages on DNS-over-HTTPS, DNS-over-QUIC, or DNS-over-gRPC listeners. A remote attacker can send a specially crafted request to cause a denial of service.
Only deployments exposing DoH, DoH3, DoQ, or DNS-over-gRPC to an attacker are vulnerable, while ordinary UDP and TCP listeners are not affected.
2) Unintended Proxy or Intermediary (CVE-ID: CVE-2026-86003)
CWE-ID: CWE-441 - Unintended Proxy or Intermediary ('Confused Deputy')
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to modify DNS records.
The vulnerability exists due to an unintended proxy or intermediary behavior in the DoH, DoH3, DoQ, and DNS-over-gRPC listeners when processing RFC 2136 UPDATE messages. A remote attacker can send an unsigned RFC 2136 UPDATE message to modify DNS records.
Exploitation requires an update-capable upstream target that trusts CoreDNS's source address or connection and does not require an attacker-unknown TSIG.
Remediation
Install update from vendor's website.