{"api_version":"1","generated_at":"2026-06-05T06:00:29+00:00","cve":"CVE-2026-43501","urls":{"html":"https://cve.report/CVE-2026-43501","api":"https://cve.report/api/cve/CVE-2026-43501.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43501","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43501"},"summary":{"title":"ipv6: rpl: reserve mac_len headroom when recompressed SRH grows","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: reserve mac_len headroom when recompressed SRH grows\n\nipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps\nthe next segment into ipv6_hdr->daddr, recompresses, then pulls the old\nheader and pushes the new one plus the IPv6 header back.  The\nrecompressed header can be larger than the received one when the swap\nreduces the common-prefix length the segments share with daddr (CmprI=0,\nCmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).\n\npskb_expand_head() was gated on segments_left == 0, so on earlier\nsegments the push consumed unchecked headroom.  Once skb_push() leaves\nfewer than skb->mac_len bytes in front of data,\nskb_mac_header_rebuild()'s call to:\n\n\tskb_set_mac_header(skb, -skb->mac_len);\n\nwill store (data - head) - mac_len into the u16 mac_header field, which\nwraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB\npast skb->head.\n\nA single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two\nsegment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one\npass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.\n\nFix this by expanding the head whenever the remaining room is less than\nthe push size plus mac_len, and request that much extra so the rebuilt\nMAC header fits afterwards.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-21 13:16:19","updated_at":"2026-06-01 17:17:07"},"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/8e8be63465a5e80394c70324603dfea1bfdad48f","name":"https://git.kernel.org/stable/c/8e8be63465a5e80394c70324603dfea1bfdad48f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c261d07a80576dc8ccf394ef8f074f8c67a06b37","name":"https://git.kernel.org/stable/c/c261d07a80576dc8ccf394ef8f074f8c67a06b37","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/0a9e8053f1f8a8e1bfc1dd61ffe67be6c1180402","name":"https://git.kernel.org/stable/c/0a9e8053f1f8a8e1bfc1dd61ffe67be6c1180402","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/bde199c72d319a4e207f88daabc888317504e2fb","name":"https://git.kernel.org/stable/c/bde199c72d319a4e207f88daabc888317504e2fb","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7398ebefbfd4f8a31d4f665a4213302fa995494b","name":"https://git.kernel.org/stable/c/7398ebefbfd4f8a31d4f665a4213302fa995494b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/4babc2d9fda2df43823b85d08a0180b68f1b0854","name":"https://git.kernel.org/stable/c/4babc2d9fda2df43823b85d08a0180b68f1b0854","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/9e6bf146b55999a095bb14f73a843942456d1adc","name":"https://git.kernel.org/stable/c/9e6bf146b55999a095bb14f73a843942456d1adc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/be1fa0aa9b4fdd5a8b7a61ba520a690a68391e6e","name":"https://git.kernel.org/stable/c/be1fa0aa9b4fdd5a8b7a61ba520a690a68391e6e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43501","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43501","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 bde199c72d319a4e207f88daabc888317504e2fb git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 be1fa0aa9b4fdd5a8b7a61ba520a690a68391e6e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 0a9e8053f1f8a8e1bfc1dd61ffe67be6c1180402 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 8e8be63465a5e80394c70324603dfea1bfdad48f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.209 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.175 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.140 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.86 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.27 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.4 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"43501","cve":"CVE-2026-43501","epss":"0.000700000","percentile":"0.215780000","score_date":"2026-06-04","updated_at":"2026-06-05 00:02:15"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv6/exthdrs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"bde199c72d319a4e207f88daabc888317504e2fb","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"be1fa0aa9b4fdd5a8b7a61ba520a690a68391e6e","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"0a9e8053f1f8a8e1bfc1dd61ffe67be6c1180402","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"8e8be63465a5e80394c70324603dfea1bfdad48f","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"4babc2d9fda2df43823b85d08a0180b68f1b0854","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"c261d07a80576dc8ccf394ef8f074f8c67a06b37","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"7398ebefbfd4f8a31d4f665a4213302fa995494b","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"},{"lessThan":"9e6bf146b55999a095bb14f73a843942456d1adc","status":"affected","version":"8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv6/exthdrs.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.7"},{"lessThan":"5.7","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.258","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.209","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.175","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.140","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.86","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.27","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.258","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.209","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.175","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.140","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.86","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.27","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.4","versionStartIncluding":"5.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc2","versionStartIncluding":"5.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: reserve mac_len headroom when recompressed SRH grows\n\nipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps\nthe next segment into ipv6_hdr->daddr, recompresses, then pulls the old\nheader and pushes the new one plus the IPv6 header back.  The\nrecompressed header can be larger than the received one when the swap\nreduces the common-prefix length the segments share with daddr (CmprI=0,\nCmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).\n\npskb_expand_head() was gated on segments_left == 0, so on earlier\nsegments the push consumed unchecked headroom.  Once skb_push() leaves\nfewer than skb->mac_len bytes in front of data,\nskb_mac_header_rebuild()'s call to:\n\n\tskb_set_mac_header(skb, -skb->mac_len);\n\nwill store (data - head) - mac_len into the u16 mac_header field, which\nwraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB\npast skb->head.\n\nA single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two\nsegment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one\npass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.\n\nFix this by expanding the head whenever the remaining room is less than\nthe push size plus mac_len, and request that much extra so the rebuilt\nMAC header fits afterwards."}],"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":"2026-06-01T16:16:09.311Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/bde199c72d319a4e207f88daabc888317504e2fb"},{"url":"https://git.kernel.org/stable/c/be1fa0aa9b4fdd5a8b7a61ba520a690a68391e6e"},{"url":"https://git.kernel.org/stable/c/0a9e8053f1f8a8e1bfc1dd61ffe67be6c1180402"},{"url":"https://git.kernel.org/stable/c/8e8be63465a5e80394c70324603dfea1bfdad48f"},{"url":"https://git.kernel.org/stable/c/4babc2d9fda2df43823b85d08a0180b68f1b0854"},{"url":"https://git.kernel.org/stable/c/c261d07a80576dc8ccf394ef8f074f8c67a06b37"},{"url":"https://git.kernel.org/stable/c/7398ebefbfd4f8a31d4f665a4213302fa995494b"},{"url":"https://git.kernel.org/stable/c/9e6bf146b55999a095bb14f73a843942456d1adc"}],"title":"ipv6: rpl: reserve mac_len headroom when recompressed SRH grows","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43501","datePublished":"2026-05-21T12:17:49.885Z","dateReserved":"2026-05-01T14:12:56.014Z","dateUpdated":"2026-06-01T16:16:09.311Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-21 13:16:19","lastModifiedDate":"2026-06-01 17:17:07","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":"43501","Ordinal":"1","Title":"ipv6: rpl: reserve mac_len headroom when recompressed SRH grows","CVE":"CVE-2026-43501","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43501","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: rpl: reserve mac_len headroom when recompressed SRH grows\n\nipv6_rpl_srh_rcv() decompresses an RFC 6554 Source Routing Header, swaps\nthe next segment into ipv6_hdr->daddr, recompresses, then pulls the old\nheader and pushes the new one plus the IPv6 header back.  The\nrecompressed header can be larger than the received one when the swap\nreduces the common-prefix length the segments share with daddr (CmprI=0,\nCmprE>0, seg[0][0] != daddr[0] gives the maximum +8 bytes).\n\npskb_expand_head() was gated on segments_left == 0, so on earlier\nsegments the push consumed unchecked headroom.  Once skb_push() leaves\nfewer than skb->mac_len bytes in front of data,\nskb_mac_header_rebuild()'s call to:\n\n\tskb_set_mac_header(skb, -skb->mac_len);\n\nwill store (data - head) - mac_len into the u16 mac_header field, which\nwraps to ~65530, and the following memmove() writes mac_len bytes ~64KiB\npast skb->head.\n\nA single AF_INET6/SOCK_RAW/IPV6_HDRINCL packet over lo with a two\nsegment type-3 SRH (CmprI=0, CmprE=15) reaches headroom 8 after one\npass; KASAN reports a 14-byte OOB write in ipv6_rthdr_rcv.\n\nFix this by expanding the head whenever the remaining room is less than\nthe push size plus mac_len, and request that much extra so the rebuilt\nMAC header fits afterwards.","Type":"Description","Title":"ipv6: rpl: reserve mac_len headroom when recompressed SRH grows"}]}}}