CVE-2026-74597

In the Linux kernel, the following vulnerability has been resolved: ip6_tunnel: clear skb2->cb[] in ip6ip6_err() ip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the quoted inner IPv6 packet, and then passes the clone to icmpv6_send(). The clone still carries the outer packet's inet6_skb_parm in skb->cb. If the outer packet had a Home Address Option, IP6CB(skb2)->dsthao remains non-zero after skb_pull(). icmpv6_send() later calls mip6_addr_swap(), which uses that stale dsthao offset against the quoted inner packet. A malformed inner destination-options header can then make the HAO lookup and address swap run past the end of the quoted packet and corrupt skb_shared_info. Clear skb2->cb[] before pulling the quoted inner IPv6 packet so the reply path does not reuse metadata left by the outer IPv6 stack.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://git.kernel.org/stable/c/0dadb0620ab65949a8bc2439dd28ea3c942fe87d
https://git.kernel.org/stable/c/44fe898df302e91c5ee5acbc71ffa74e78e6c183
https://git.kernel.org/stable/c/484134e1eb07d700a73b1e4bbf3fb503e299be60
https://git.kernel.org/stable/c/4eb15c465337b18f44716c499cd6ad63eee0ad54
https://git.kernel.org/stable/c/64e41736a26f37ab6215bc2e6df125df05aceb08
https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b
https://git.kernel.org/stable/c/f803c086399da277b5d0ff36a107d0f162751800
https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-22 16:16

Updated : 2026-08-25 06:18

NVD link : CVE-2026-74597

Mitre link : CVE-2026-74597

CVE.ORG link : CVE-2026-74597

JSON object : View

Products Affected

No product.

CWE

No CWE.

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"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/b6816536a2990c0db44a26130a03e40b441e829b", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/f803c086399da277b5d0ff36a107d0f162751800", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/fbf40faa0414b753212494ad197542002e66ed9e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Received", "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: clear skb2->cb[] in ip6ip6_err()\n\nip6ip6_err() clones an outer IPv6 ICMP error skb, pulls it to the\nquoted inner IPv6 packet, and then passes the clone to icmpv6_send().\nThe clone still carries the outer packet's inet6_skb_parm in skb->cb.\n\nIf the outer packet had a Home Address Option, IP6CB(skb2)->dsthao\nremains non-zero after skb_pull(). icmpv6_send() later calls\nmip6_addr_swap(), which uses that stale dsthao offset against the quoted\ninner packet. A malformed inner destination-options header can then make\nthe HAO lookup and address swap run past the end of the quoted packet\nand corrupt skb_shared_info.\n\nClear skb2->cb[] before pulling the quoted inner IPv6 packet so the\nreply path does not reuse metadata left by the outer IPv6 stack."}], "lastModified": "2026-08-25T06:18:35.440", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}