{"api_version":"1","generated_at":"2026-05-13T07:41:18+00:00","cve":"CVE-2026-43186","urls":{"html":"https://cve.report/CVE-2026-43186","api":"https://cve.report/api/cve/CVE-2026-43186.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43186","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43186"},"summary":{"title":"ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace->nodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace->type (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00).","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-06 12:16:37","updated_at":"2026-05-11 20:40:56"},"problem_types":["CWE-787"],"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/0591d6509c2ff13f09ea2998434aba0c0472e978","name":"https://git.kernel.org/stable/c/0591d6509c2ff13f09ea2998434aba0c0472e978","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc","name":"https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f","name":"https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96b","name":"https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143","name":"https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23b","name":"https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637","name":"https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43186","name":"CVE 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the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace->nodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace->type (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00)."}],"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":"2026-05-08T12:41:04.575Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/f4d9d4b8fd839719d564651671e24c62c545c23b"},{"url":"https://git.kernel.org/stable/c/fb3c662fafebc5b9d74417ed1de8759f6bb72143"},{"url":"https://git.kernel.org/stable/c/632d233cf2e64a46865ae2c064ae3c9df7c8864f"},{"url":"https://git.kernel.org/stable/c/0591d6509c2ff13f09ea2998434aba0c0472e978"},{"url":"https://git.kernel.org/stable/c/e90346a2f1e8917d5760a44a1f61c44e3b36d96b"},{"url":"https://git.kernel.org/stable/c/ea3632aefc04205436868541638e26f4a74d5637"},{"url":"https://git.kernel.org/stable/c/6db8b56eed62baacaf37486e83378a72635c04cc"}],"title":"ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43186","datePublished":"2026-05-06T11:27:57.053Z","dateReserved":"2026-05-01T14:12:55.991Z","dateUpdated":"2026-05-08T12:41:04.575Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-06 12:16:37","lastModifiedDate":"2026-05-11 20:40:56","problem_types":["CWE-787"],"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":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15","versionEndExcluding":"5.15.202","matchCriteriaId":"B0330CE4-09CE-43EF-A9C8-CD49FFD1DC98"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.165","matchCriteriaId":"797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.128","matchCriteriaId":"851E9353-6C09-4CC9-877E-E09DB164A3C2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.75","matchCriteriaId":"BCE16369-98ED-41CF-8995-DFDC10B288D2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.16","matchCriteriaId":"B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.19","versionEndExcluding":"6.19.6","matchCriteriaId":"373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43186","Ordinal":"1","Title":"ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data(","CVE":"CVE-2026-43186","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43186","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data()\n\nOn the receive path, __ioam6_fill_trace_data() uses trace->nodelen\nto decide how much data to write for each node. It trusts this field\nas-is from the incoming packet, with no consistency check against\ntrace->type (the 24-bit field that tells which data items are\npresent). A crafted packet can set nodelen=0 while setting type bits\n0-21, causing the function to write ~100 bytes past the allocated\nregion (into skb_shared_info), which corrupts adjacent heap memory\nand leads to a kernel panic.\n\nAdd a shared helper ioam6_trace_compute_nodelen() in ioam6.c to\nderive the expected nodelen from the type field, and use it:\n\n  - in ioam6_iptunnel.c (send path, existing validation) to replace\n    the open-coded computation;\n  - in exthdrs.c (receive path, ipv6_hop_ioam) to drop packets whose\n    nodelen is inconsistent with the type field, before any data is\n    written.\n\nPer RFC 9197, bits 12-21 are each short (4-octet) fields, so they\nare included in IOAM6_MASK_SHORT_FIELDS (changed from 0xff100000 to\n0xff1ffc00).","Type":"Description","Title":"ipv6: ioam: fix heap buffer overflow in __ioam6_fill_trace_data("}]}}}