CVE-2025-23018: IPv4-in-IPv6 and IPv6-in-IPv6 tunneling (RFC 2473) do not require the validation or verification of the source

This month

MEDIUM 5.4REMOTEMITIGATE

CVE-2025-23018 is a medium-severity flaw (CVSS 5.4) affecting ipv6. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

IPv4-in-IPv6 and IPv6-in-IPv6 tunneling (RFC 2473) do not require the validation or verification of the source of a network packet, allowing an attacker to spoof and route arbitrary traffic via an exposed network interface. This is a similar issue to CVE-2020-10136.

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.0% (top 36%)
CISA exploited list	No
Weakness	CWE-940
Published	2025-01-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: ietf

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-01-14 20:15 UTCPublished CVE record published
2026-06-17 08:51 UTCUpdated Record last modified

ietf ipv6 MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy ipv6 || rpm -q ipv6 || ipv6 --version

No fixed or unaffected release known

Apply the vendor mitigation from the advisory, disable the affected feature, or restrict network access.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-23018?

ipv6: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2025-23018 being exploited?

CVE-2025-23018 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2025-23018 affect?

CVE-2025-23018 affects ipv6. Severity is medium (CVSS 5.4). IPv4-in-IPv6 and IPv6-in-IPv6 tunneling (RFC 2473) do not require the validation or verification of the source of a network packet, allowing an attacker to spoof and route arbitrary traffic via an exposed network interface. This is a simila

How urgent is CVE-2025-23018?

Priority 40/100. Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-23019 MEDIUM 5.4 MITIGATE IPv6-in-IPv4 tunneling (RFC 4213) allows an attacker to spoof and route traffic via an exposed network interfa

References

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