{"api_version":"1","generated_at":"2026-04-25T19:49:30+00:00","cve":"CVE-2026-31630","urls":{"html":"https://cve.report/CVE-2026-31630","api":"https://cve.report/api/cve/CVE-2026-31630.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31630","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31630"},"summary":{"title":"rxrpc: proc: size address buffers for %pISpc output","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter's maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-24 15:16:42","updated_at":"2026-04-24 17:51:40"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9","name":"https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272","name":"https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874","name":"https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31630","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31630","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 75b54cb57ca34cbe7a87c6ac757c55360a624590 db297c78ce537c9ac96f0eda9b25ad72c8caefa9 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 75b54cb57ca34cbe7a87c6ac757c55360a624590 10ebed83f9f6414af4e85bc85ffaeda7effdd874 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 75b54cb57ca34cbe7a87c6ac757c55360a624590 a44ce6aa2efb61fe44f2cfab72bb01544bbca272 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.23 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.13 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/rxrpc/proc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"db297c78ce537c9ac96f0eda9b25ad72c8caefa9","status":"affected","version":"75b54cb57ca34cbe7a87c6ac757c55360a624590","versionType":"git"},{"lessThan":"10ebed83f9f6414af4e85bc85ffaeda7effdd874","status":"affected","version":"75b54cb57ca34cbe7a87c6ac757c55360a624590","versionType":"git"},{"lessThan":"a44ce6aa2efb61fe44f2cfab72bb01544bbca272","status":"affected","version":"75b54cb57ca34cbe7a87c6ac757c55360a624590","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/rxrpc/proc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.9"},{"lessThan":"4.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.23","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.13","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.23","versionStartIncluding":"4.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.13","versionStartIncluding":"4.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"4.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter's maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example"}],"providerMetadata":{"dateUpdated":"2026-04-24T14:44:46.606Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9"},{"url":"https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874"},{"url":"https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272"}],"title":"rxrpc: proc: size address buffers for %pISpc output","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31630","datePublished":"2026-04-24T14:44:46.606Z","dateReserved":"2026-03-09T15:48:24.124Z","dateUpdated":"2026-04-24T14:44:46.606Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-24 15:16:42","lastModifiedDate":"2026-04-24 17:51:40","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31630","Ordinal":"1","Title":"rxrpc: proc: size address buffers for %pISpc output","CVE":"CVE-2026-31630","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31630","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter's maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example","Type":"Description","Title":"rxrpc: proc: size address buffers for %pISpc output"}]}}}