Denial of service via zero-length IPv6 option
Published Jul 1, 2026 · Updated Jul 1, 2026
Denial of service in dhcpcd on Red Hat Enterprise Linux 10 allows attackers to consume CPU via a malformed IPv6 Router Advertisement. The ipv6nd_handlera parser records an option length of zero, fails to discard the retained packet, and later advances its parsing loop by zero bytes. Exploitation requires an unauthenticated attacker on the same Layer-2 segment and enabled IPv6 Router Advertisement processing; dhcpcd becomes unresponsive and consumes excessive CPU.
Summary
What happened
Denial of service in dhcpcd on Red Hat Enterprise Linux 10 allows attackers to consume CPU via a malformed IPv6 Router Advertisement. The ipv6nd_handlera parser records an option length of zero, fails to discard the retained packet, and later advances its parsing loop by zero bytes. Exploitation requires an unauthenticated attacker on the same Layer-2 segment and enabled IPv6 Router Advertisement processing; dhcpcd becomes unresponsive and consumes excessive CPU.
The record
- CVE
- CVE-2026-14258
- Published
- Jul 1, 2026
- Updated
- Jul 1, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-835, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 1, 2026CVE publishedPublication date reported by the CVE source.
- Jul 1, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Scapy zero-length Router Advertisement reproducerproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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