{"api_version":"1","generated_at":"2026-07-23T23:18:46+00:00","cve":"CVE-2026-63925","urls":{"html":"https://cve.report/CVE-2026-63925","api":"https://cve.report/api/cve/CVE-2026-63925.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63925","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63925"},"summary":{"title":"macsec: fix replay protection at XPN lower-PN wrap","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: fix replay protection at XPN lower-PN wrap\n\nIn macsec_post_decrypt(), when pn is U32_MAX, pn + 1 overflows u32 to 0\nand the first branch never fires. If next_pn_halves.lower is also in the\nupper half, pn_same_half(pn, lower) is true and the XPN else-if does not\nfire either, leaving next_pn_halves unchanged. An attacker that captures\nthe legitimate frame carrying pn == 0xFFFFFFFF on an XPN association\ncan then replay it indefinitely, since lowest_pn never rises above\nthe captured pn and macsec_decrypt() reconstructs the same IV.\n\nExtend the XPN else-if to also fire when pn + 1 wraps to 0, so receipt\nof pn == U32_MAX advances next_pn_halves to (upper + 1, 0).","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 16:17:10","updated_at":"2026-07-20 15:16:56"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"8.1","severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"8.1","severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","data":{"baseScore":8.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/79495a1b0944fe31ffd54b54b00211b493590d62","name":"https://git.kernel.org/stable/c/79495a1b0944fe31ffd54b54b00211b493590d62","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/23c0e230eab397d7f68be2538790ac41d3bb91fd","name":"https://git.kernel.org/stable/c/23c0e230eab397d7f68be2538790ac41d3bb91fd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d55acbe577db892b60547b6ef1c020b359331a6d","name":"https://git.kernel.org/stable/c/d55acbe577db892b60547b6ef1c020b359331a6d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652","name":"https://git.kernel.org/stable/c/6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e68842b3356471ba56c882209f324613dac47f64","name":"https://git.kernel.org/stable/c/e68842b3356471ba56c882209f324613dac47f64","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/679e13a65e68a67c8b3c0467c02ee89157ec6f0f","name":"https://git.kernel.org/stable/c/679e13a65e68a67c8b3c0467c02ee89157ec6f0f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d15130461df388136b62a7b0ce9f66e7e2fa9ff1","name":"https://git.kernel.org/stable/c/d15130461df388136b62a7b0ce9f66e7e2fa9ff1","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/dd7306779c6ce1238f4cdc34f3c1f2246b854457","name":"https://git.kernel.org/stable/c/dd7306779c6ce1238f4cdc34f3c1f2246b854457","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63925","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63925","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a21ecf0e033807b976967286e6c392f48ee2049f dd7306779c6ce1238f4cdc34f3c1f2246b854457 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a21ecf0e033807b976967286e6c392f48ee2049f d15130461df388136b62a7b0ce9f66e7e2fa9ff1 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a21ecf0e033807b976967286e6c392f48ee2049f 23c0e230eab397d7f68be2538790ac41d3bb91fd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a21ecf0e033807b976967286e6c392f48ee2049f 679e13a65e68a67c8b3c0467c02ee89157ec6f0f 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 * 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the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: fix replay protection at XPN lower-PN wrap\n\nIn macsec_post_decrypt(), when pn is U32_MAX, pn + 1 overflows u32 to 0\nand the first branch never fires. If next_pn_halves.lower is also in the\nupper half, pn_same_half(pn, lower) is true and the XPN else-if does not\nfire either, leaving next_pn_halves unchanged. An attacker that captures\nthe legitimate frame carrying pn == 0xFFFFFFFF on an XPN association\ncan then replay it indefinitely, since lowest_pn never rises above\nthe captured pn and macsec_decrypt() reconstructs the same IV.\n\nExtend the XPN else-if to also fire when pn + 1 wraps to 0, so receipt\nof pn == U32_MAX advances next_pn_halves to (upper + 1, 0)."}],"metrics":[{"cvssV3_1":{"baseScore":8.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:41:35.092Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/dd7306779c6ce1238f4cdc34f3c1f2246b854457"},{"url":"https://git.kernel.org/stable/c/d15130461df388136b62a7b0ce9f66e7e2fa9ff1"},{"url":"https://git.kernel.org/stable/c/23c0e230eab397d7f68be2538790ac41d3bb91fd"},{"url":"https://git.kernel.org/stable/c/679e13a65e68a67c8b3c0467c02ee89157ec6f0f"},{"url":"https://git.kernel.org/stable/c/79495a1b0944fe31ffd54b54b00211b493590d62"},{"url":"https://git.kernel.org/stable/c/6d00f5c7e5ff7ec4795b7f5f8ed88bd346641652"},{"url":"https://git.kernel.org/stable/c/d55acbe577db892b60547b6ef1c020b359331a6d"},{"url":"https://git.kernel.org/stable/c/e68842b3356471ba56c882209f324613dac47f64"}],"title":"macsec: fix replay protection at XPN lower-PN wrap","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63925","datePublished":"2026-07-19T14:55:26.442Z","dateReserved":"2026-07-19T07:54:57.021Z","dateUpdated":"2026-07-20T13:41:35.092Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 16:17:10","lastModifiedDate":"2026-07-20 15:16:56","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH","attackVector":"ADJACENT_NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":5.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63925","Ordinal":"1","Title":"macsec: fix replay protection at XPN lower-PN wrap","CVE":"CVE-2026-63925","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63925","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nmacsec: fix replay protection at XPN lower-PN wrap\n\nIn macsec_post_decrypt(), when pn is U32_MAX, pn + 1 overflows u32 to 0\nand the first branch never fires. If next_pn_halves.lower is also in the\nupper half, pn_same_half(pn, lower) is true and the XPN else-if does not\nfire either, leaving next_pn_halves unchanged. An attacker that captures\nthe legitimate frame carrying pn == 0xFFFFFFFF on an XPN association\ncan then replay it indefinitely, since lowest_pn never rises above\nthe captured pn and macsec_decrypt() reconstructs the same IV.\n\nExtend the XPN else-if to also fire when pn + 1 wraps to 0, so receipt\nof pn == U32_MAX advances next_pn_halves to (upper + 1, 0).","Type":"Description","Title":"macsec: fix replay protection at XPN lower-PN wrap"}]}}}