{"api_version":"1","generated_at":"2026-07-23T15:32:36+00:00","cve":"CVE-2026-63993","urls":{"html":"https://cve.report/CVE-2026-63993","api":"https://cve.report/api/cve/CVE-2026-63993.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63993","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63993"},"summary":{"title":"vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()\n\nskb_tunnel_check_pmtu() can change skb->head.\n\nReusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF.\n\nUse instead ip_hdr(skb) as done in drivers/net/bareudp.c\nand drivers/net/geneve.c.\n\nFound by Sashiko.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:38","updated_at":"2026-07-20 15:17:00"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/a493efd4336cf19122ae0e4cbb3d31b32d70deea","name":"https://git.kernel.org/stable/c/a493efd4336cf19122ae0e4cbb3d31b32d70deea","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/609e63312c29aad18026a1d3222e123d4b6b0feb","name":"https://git.kernel.org/stable/c/609e63312c29aad18026a1d3222e123d4b6b0feb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5303925e360527243b46a440a04667826bbc72b7","name":"https://git.kernel.org/stable/c/5303925e360527243b46a440a04667826bbc72b7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dc3bfa050f873371e745bdf478b1f5b738e5733d","name":"https://git.kernel.org/stable/c/dc3bfa050f873371e745bdf478b1f5b738e5733d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9257f56ac47ef1976bcd056cf986a9988eeec67a","name":"https://git.kernel.org/stable/c/9257f56ac47ef1976bcd056cf986a9988eeec67a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7d9ef0cb271555d8cf39fefe6c981e1493b25ecf","name":"https://git.kernel.org/stable/c/7d9ef0cb271555d8cf39fefe6c981e1493b25ecf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8d435d68d71fb875876b722f4136caf74f2f48bd","name":"https://git.kernel.org/stable/c/8d435d68d71fb875876b722f4136caf74f2f48bd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6b8bfce9d2f774d2c2243e0248e03efb99bba6c0","name":"https://git.kernel.org/stable/c/6b8bfce9d2f774d2c2243e0248e03efb99bba6c0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63993","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63993","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 9257f56ac47ef1976bcd056cf986a9988eeec67a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 8d435d68d71fb875876b722f4136caf74f2f48bd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f dc3bfa050f873371e745bdf478b1f5b738e5733d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.210 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.176 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.143 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.93 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.35 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.12 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"63993","cve":"CVE-2026-63993","epss":"0.001760000","percentile":"0.073850000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:13"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/net/vxlan/vxlan_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6b8bfce9d2f774d2c2243e0248e03efb99bba6c0","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"9257f56ac47ef1976bcd056cf986a9988eeec67a","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"8d435d68d71fb875876b722f4136caf74f2f48bd","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"dc3bfa050f873371e745bdf478b1f5b738e5733d","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"609e63312c29aad18026a1d3222e123d4b6b0feb","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"5303925e360527243b46a440a04667826bbc72b7","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"a493efd4336cf19122ae0e4cbb3d31b32d70deea","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"},{"lessThan":"7d9ef0cb271555d8cf39fefe6c981e1493b25ecf","status":"affected","version":"4cb47a8644cc9eb8ec81190a50e79e6530d0297f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/net/vxlan/vxlan_core.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.259","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.210","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.176","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.143","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.93","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.35","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.12","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.259","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.210","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.176","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.143","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.93","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.35","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.12","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"5.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()\n\nskb_tunnel_check_pmtu() can change skb->head.\n\nReusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF.\n\nUse instead ip_hdr(skb) as done in drivers/net/bareudp.c\nand drivers/net/geneve.c.\n\nFound by Sashiko."}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:42:08.907Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/6b8bfce9d2f774d2c2243e0248e03efb99bba6c0"},{"url":"https://git.kernel.org/stable/c/9257f56ac47ef1976bcd056cf986a9988eeec67a"},{"url":"https://git.kernel.org/stable/c/8d435d68d71fb875876b722f4136caf74f2f48bd"},{"url":"https://git.kernel.org/stable/c/dc3bfa050f873371e745bdf478b1f5b738e5733d"},{"url":"https://git.kernel.org/stable/c/609e63312c29aad18026a1d3222e123d4b6b0feb"},{"url":"https://git.kernel.org/stable/c/5303925e360527243b46a440a04667826bbc72b7"},{"url":"https://git.kernel.org/stable/c/a493efd4336cf19122ae0e4cbb3d31b32d70deea"},{"url":"https://git.kernel.org/stable/c/7d9ef0cb271555d8cf39fefe6c981e1493b25ecf"}],"title":"vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63993","datePublished":"2026-07-19T14:56:13.218Z","dateReserved":"2026-07-19T07:54:57.025Z","dateUpdated":"2026-07-20T13:42:08.907Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 16:17:38","lastModifiedDate":"2026-07-20 15:17:00","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63993","Ordinal":"1","Title":"vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check","CVE":"CVE-2026-63993","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63993","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()\n\nskb_tunnel_check_pmtu() can change skb->head.\n\nReusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF.\n\nUse instead ip_hdr(skb) as done in drivers/net/bareudp.c\nand drivers/net/geneve.c.\n\nFound by Sashiko.","Type":"Description","Title":"vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check"}]}}}