{"cve":"CVE-2026-63992","nvd":{"published":"2026-07-19T16:17:38.700","modified":"2026-10-19T21:17:16.970","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntunnels: do not assume transport header in iptunnel_pmtud_check_icmp()\n\nIn some cases, iptunnel_pmtud_check_icmp() can be called while\nskb transport header is not set.\n\nThis triggers an out-of-bound access, because\n(typeof(skb->transport_header))~0U is 65535.\n\nAccess the icmp header based on IPv4 network header,\nafter making sure icmp->type is present in skb linear part.\n\nNote that iptunnel_pmtud_check_icmpv6()) is fine.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1},"cwes":["CWE-125"],"references":["https://git.kernel.org/stable/c/43368636c663cff6e59dde93cf4b8e43ac28eb93","https://git.kernel.org/stable/c/509323077ef79a26ba0c60bb556e45c12c398b2d","https://git.kernel.org/stable/c/5a92cb45e34749865d03daf8d3500f77b5f6644c","https://git.kernel.org/stable/c/7f4f7efe7f30edd29c4988de01728bf2398217e4","https://git.kernel.org/stable/c/a096b6e34f602950af9a2b0856cd93a5f4c276d7"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-63992","score":0.00514,"percentile":0.43527,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}