{"id":"CVE-2026-63824","state":"PUBLISHED","title":"KEYS: fix overflow in keyctl_pkey_params_get_2()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKEYS: fix overflow in keyctl_pkey_params_get_2()\n\nThe length for the internal output buffer is calculated incorrectly, which\ncan result overflow when a too small buffer is provided.\n\nFix the bug by allocating internal output with the size of the maximum\nlength of the cryptographic primitive instead of caller provided size.","publishedAt":"2026-07-19T12:02:20.406Z","updatedAt":"2026-10-19T20:07:48.872Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"622ec2dcd59f21623f2a7ab773c80ceb7d555e3a","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"b1e247338bc71826a2d2def3e0874c34749df69a","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"5966e4e2ba213ab7ad559166152eb4f1f170dd2c","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"5165f1cc727f1322456735df212d8e26ec237a8d","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"b11c1fa32667692a2c0566e10163758e786e430c","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"670fc6a311ed321522b7fff92cf0fc376b4f6e78","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/keyctl_pkey.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.260","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.211","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.177","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.144","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.95","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.38","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.3","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/keyctl_pkey.c"]}],"references":["https://git.kernel.org/stable/c/622ec2dcd59f21623f2a7ab773c80ceb7d555e3a","https://git.kernel.org/stable/c/b1e247338bc71826a2d2def3e0874c34749df69a","https://git.kernel.org/stable/c/0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3","https://git.kernel.org/stable/c/5966e4e2ba213ab7ad559166152eb4f1f170dd2c","https://git.kernel.org/stable/c/5165f1cc727f1322456735df212d8e26ec237a8d","https://git.kernel.org/stable/c/b11c1fa32667692a2c0566e10163758e786e430c","https://git.kernel.org/stable/c/670fc6a311ed321522b7fff92cf0fc376b4f6e78","https://git.kernel.org/stable/c/cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b"],"weaknesses":["CWE-787"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63824.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63824","state":"PUBLISHED","datePublished":"2026-07-19T12:02:20.406Z","dateUpdated":"2026-10-19T20:07:48.872Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.014Z"},"containers":{"cna":{"title":"KEYS: fix overflow in keyctl_pkey_params_get_2()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKEYS: fix overflow in keyctl_pkey_params_get_2()\n\nThe length for the internal output buffer is calculated incorrectly, which\ncan result overflow when a too small buffer is provided.\n\nFix the bug by allocating internal output with the size of the maximum\nlength of the cryptographic primitive instead of caller provided size."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"622ec2dcd59f21623f2a7ab773c80ceb7d555e3a","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"b1e247338bc71826a2d2def3e0874c34749df69a","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"5966e4e2ba213ab7ad559166152eb4f1f170dd2c","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"5165f1cc727f1322456735df212d8e26ec237a8d","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"b11c1fa32667692a2c0566e10163758e786e430c","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"670fc6a311ed321522b7fff92cf0fc376b4f6e78","versionType":"git"},{"version":"00d60fd3b93219ea854220f0fd264b86398cbc53","status":"affected","lessThan":"cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/keyctl_pkey.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.20","versionType":"semver"},{"version":"5.10.260","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.211","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.177","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.144","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.95","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.38","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.3","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["security/keys/keyctl_pkey.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/622ec2dcd59f21623f2a7ab773c80ceb7d555e3a"},{"url":"https://git.kernel.org/stable/c/b1e247338bc71826a2d2def3e0874c34749df69a"},{"url":"https://git.kernel.org/stable/c/0f3058d7d26f81df9b68a18ddbe164bdc3c5eff3"},{"url":"https://git.kernel.org/stable/c/5966e4e2ba213ab7ad559166152eb4f1f170dd2c"},{"url":"https://git.kernel.org/stable/c/5165f1cc727f1322456735df212d8e26ec237a8d"},{"url":"https://git.kernel.org/stable/c/b11c1fa32667692a2c0566e10163758e786e430c"},{"url":"https://git.kernel.org/stable/c/670fc6a311ed321522b7fff92cf0fc376b4f6e78"},{"url":"https://git.kernel.org/stable/c/cb481e59ea6cae3b7796ac1d7a22b6b24c3f3c0b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is reachable only through the keyctl(2) syscall (KEYCTL_PKEY_ENCRYPT, KEYCTL_PKEY_DECRYPT, or KEYCTL_PKEY_SIGN); there is no network, adjacent, or physical attack path to the affected code.\nAC:L - An attacker fully controls the undersized out_len parameter and can reliably trigger the bug on demand with no races or victim-dependent state; CONFIG_ASYMMETRIC_KEY_TYPE is commonly enabled on server and desktop kernels.\nPR:L - Exploitation requires KEY_NEED_SEARCH on an asymmetric key, which any unprivileged local user can satisfy by loading their own RSA/EC key into a session keyring; no real root or init-namespace capabilities are needed.\nUI:N - Exploitation requires only attacker-initiated keyctl calls and does not depend on any victim user action such as opening a file or mounting a filesystem.\nS:U - Impact is confined to kernel heap memory corruption and privilege escalation within the same kernel security boundary; this is not a VM escape, sandbox escape, or cross-authority boundary violation.\nC:H - When out_len is smaller than the cryptographic output (including out_len=0 where kmalloc(0) yields ZERO_SIZE_PTR), asym_eds_op returns the full primitive output size and copy_to_user reads far beyond the allocated buffer, leaking adjacent kernel heap contents to userspace.\nI:H - The undersized kmalloc buffer is passed directly as the crypto output target; asymmetric operations can write up to the primitive maximum (hundreds of bytes for RSA-4096) past the allocation, enabling heap corruption and potential control-flow hijacking.\nA:H - Heap out-of-bounds read/write against kmalloc objects or writes through ZERO_SIZE_PTR can cause kernel oops, panic, or KASAN-detected corruption, satisfying high availability impact."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:51:32.494Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.10.260"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.15.211"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.1.177"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.6.144"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.12.95"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"6.18.38"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.1.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-63824","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:31:12.388673Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-787","lang":"en","type":"CWE","description":"CWE-787 Out-of-bounds Write"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:07:48.872Z"}}]}}}