CVE-2026-63993 (GCVE-0-2026-63993)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-10-16 15:42
VLAI
Title
vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
Summary
In the Linux kernel, the following vulnerability has been resolved: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: none Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-16 15:34 UTC
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 6996 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 9257f56ac47ef1976bcd056cf986a9988eeec67a (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 8d435d68d71fb875876b722f4136caf74f2f48bd (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < dc3bfa050f873371e745bdf478b1f5b738e5733d (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 609e63312c29aad18026a1d3222e123d4b6b0feb (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 5303925e360527243b46a440a04667826bbc72b7 (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < a493efd4336cf19122ae0e4cbb3d31b32d70deea (git)
Affected: 4cb47a8644cc9eb8ec81190a50e79e6530d0297f , < 7d9ef0cb271555d8cf39fefe6c981e1493b25ecf (git)
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Linux Linux Affected: 5.9
Unaffected: 0 , < 5.9 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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      "current_release_date": "2026-10-16T17:13:09+00:00",
      "cve": "CVE-2026-63993",
      "id": "CVE-2026-63993",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:fixed": "919",
      "product_status:known_affected": "22",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63993.json",
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      "product_status:known_not_affected": "56",
      "product_status:recommended": "270",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-63993",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-63993.json",
      "version": "11"
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              "shortName": "CISA-ADP"
            },
            "title": "CISA ADP Vulnrichment"
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}



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