{"api_version":"1","generated_at":"2026-07-23T18:59:41+00:00","cve":"CVE-2026-63872","urls":{"html":"https://cve.report/CVE-2026-63872","api":"https://cve.report/api/cve/CVE-2026-63872.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-63872","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-63872"},"summary":{"title":"esp: fix page frag reference leak on skb_to_sgvec failure","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nesp: fix page frag reference leak on skb_to_sgvec failure\n\nIn esp_output_tail(), when esp->inplace is false, the old skb page frags\nare replaced with a new page from the xfrm page_frag cache. The source\nscatterlist (sg) is built from the old frags before the replacement, and\nesp_ssg_unref() is responsible for releasing the old page references\nafter the crypto operation completes.\n\nHowever, if the second skb_to_sgvec() call (which builds the destination\nscatterlist from the new page) fails, the code jumps to error_free which\nonly calls kfree(tmp). The old page frag references captured in the\nsource scatterlist are never released:\n\n  1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page)\n  2. nr_frags is set to 1 and frag[0] is replaced with the new page\n  3. Second skb_to_sgvec() fails -> goto error_free\n  4. kfree(tmp) frees the sg[] memory but old frags are not unref'd\n  5. kfree_skb() only releases frag[0] (the new page), not the old ones\n\nFix this by adding a bool parameter to esp_ssg_unref() that, when true,\nunconditionally unrefs the source scatterlist frags without checking\nreq->src and req->dst, since those fields are not yet initialized by\naead_request_set_crypt() at the point of the error. Existing callers\npass false to preserve the original behavior.\n\nThe same issue exists in both esp4 and esp6 as the code is identical.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-19 15:16:54","updated_at":"2026-07-20 15:16:53"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/2982e599fff6faa21c8df147d96fc7af6c1a2f24","name":"https://git.kernel.org/stable/c/2982e599fff6faa21c8df147d96fc7af6c1a2f24","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e705b8ff4dd38fb8fe4e6fdc5378a86acea4feb5","name":"https://git.kernel.org/stable/c/e705b8ff4dd38fb8fe4e6fdc5378a86acea4feb5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-63872","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-63872","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cac2661c53f35cbe651bef9b07026a5a05ab8ce0 e705b8ff4dd38fb8fe4e6fdc5378a86acea4feb5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected cac2661c53f35cbe651bef9b07026a5a05ab8ce0 2982e599fff6faa21c8df147d96fc7af6c1a2f24 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.13 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":"63872","cve":"CVE-2026-63872","epss":"0.001450000","percentile":"0.042080000","score_date":"2026-07-20","updated_at":"2026-07-21 00:13:14"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/ipv4/esp4.c","net/ipv6/esp6.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"e705b8ff4dd38fb8fe4e6fdc5378a86acea4feb5","status":"affected","version":"cac2661c53f35cbe651bef9b07026a5a05ab8ce0","versionType":"git"},{"lessThan":"2982e599fff6faa21c8df147d96fc7af6c1a2f24","status":"affected","version":"cac2661c53f35cbe651bef9b07026a5a05ab8ce0","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/ipv4/esp4.c","net/ipv6/esp6.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.11"},{"lessThan":"4.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.13","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":"7.0.13","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1","versionStartIncluding":"4.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nesp: fix page frag reference leak on skb_to_sgvec failure\n\nIn esp_output_tail(), when esp->inplace is false, the old skb page frags\nare replaced with a new page from the xfrm page_frag cache. The source\nscatterlist (sg) is built from the old frags before the replacement, and\nesp_ssg_unref() is responsible for releasing the old page references\nafter the crypto operation completes.\n\nHowever, if the second skb_to_sgvec() call (which builds the destination\nscatterlist from the new page) fails, the code jumps to error_free which\nonly calls kfree(tmp). The old page frag references captured in the\nsource scatterlist are never released:\n\n  1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page)\n  2. nr_frags is set to 1 and frag[0] is replaced with the new page\n  3. Second skb_to_sgvec() fails -> goto error_free\n  4. kfree(tmp) frees the sg[] memory but old frags are not unref'd\n  5. kfree_skb() only releases frag[0] (the new page), not the old ones\n\nFix this by adding a bool parameter to esp_ssg_unref() that, when true,\nunconditionally unrefs the source scatterlist frags without checking\nreq->src and req->dst, since those fields are not yet initialized by\naead_request_set_crypt() at the point of the error. Existing callers\npass false to preserve the original behavior.\n\nThe same issue exists in both esp4 and esp6 as the code is identical."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"providerMetadata":{"dateUpdated":"2026-07-20T13:41:04.348Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/e705b8ff4dd38fb8fe4e6fdc5378a86acea4feb5"},{"url":"https://git.kernel.org/stable/c/2982e599fff6faa21c8df147d96fc7af6c1a2f24"}],"title":"esp: fix page frag reference leak on skb_to_sgvec failure","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-63872","datePublished":"2026-07-19T14:18:40.499Z","dateReserved":"2026-07-19T07:54:57.017Z","dateUpdated":"2026-07-20T13:41:04.348Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-19 15:16:54","lastModifiedDate":"2026-07-20 15:16:53","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:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"63872","Ordinal":"1","Title":"esp: fix page frag reference leak on skb_to_sgvec failure","CVE":"CVE-2026-63872","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"63872","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nesp: fix page frag reference leak on skb_to_sgvec failure\n\nIn esp_output_tail(), when esp->inplace is false, the old skb page frags\nare replaced with a new page from the xfrm page_frag cache. The source\nscatterlist (sg) is built from the old frags before the replacement, and\nesp_ssg_unref() is responsible for releasing the old page references\nafter the crypto operation completes.\n\nHowever, if the second skb_to_sgvec() call (which builds the destination\nscatterlist from the new page) fails, the code jumps to error_free which\nonly calls kfree(tmp). The old page frag references captured in the\nsource scatterlist are never released:\n\n  1. sg[] is built from old frags via skb_to_sgvec() (no extra get_page)\n  2. nr_frags is set to 1 and frag[0] is replaced with the new page\n  3. Second skb_to_sgvec() fails -> goto error_free\n  4. kfree(tmp) frees the sg[] memory but old frags are not unref'd\n  5. kfree_skb() only releases frag[0] (the new page), not the old ones\n\nFix this by adding a bool parameter to esp_ssg_unref() that, when true,\nunconditionally unrefs the source scatterlist frags without checking\nreq->src and req->dst, since those fields are not yet initialized by\naead_request_set_crypt() at the point of the error. Existing callers\npass false to preserve the original behavior.\n\nThe same issue exists in both esp4 and esp6 as the code is identical.","Type":"Description","Title":"esp: fix page frag reference leak on skb_to_sgvec failure"}]}}}