CVE-2026-89766

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89766", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.764Z", "datePublished": "2026-09-11T19:47:06.597Z", "dateUpdated": "2026-10-19T08:52:19.816Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:52:19.816Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npidfd: hold exec_update_lock around namespace ioctl\n\nThe PIDFD_GET_*_NAMESPACE ioctls in pidfd_ioctl() perform a filesystem\ncredentials ptrace access check before handing out a namespace file\ndescriptor. The accompanying comment states that the code \"mirrors nsfs\nbehavior\", but, unlike the corresponding procfs paths, it does so without\nholding the target task's exec_update_lock.\n\nproc_ns_get_link() and proc_ns_readlink() both take exec_update_lock for\nreading around the ptrace check and the namespace lookup, so that the\ncredentials used for the access decision match those of the task when its\nnamespace is read. Without it, a caller can pass the check against the\ntarget's old credentials and then read the namespace after the target has\nexecve()'d a setuid binary and committed new credentials -- accessing\nnamespace information it should have been denied.\n\nHold exec_update_lock for reading around the ptrace check and the\nnamespace lookup so that pidfd truly mirrors nsfs behavior, as the comment\nalready claims. open_namespace() itself runs outside the lock: once a\nnamespace reference is obtained it carries its own refcount and is opened\nwith the caller's own credentials, so a concurrent execve() on the target\ncan no longer affect the outcome."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/pidfs.c"], "versions": [{"version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "lessThan": "bac2f1913a216677c2c220d7bb352dd0330065ca", "status": "affected", "versionType": "git"}, {"version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "lessThan": "cf24ce48d60225fdbee68ed2058763a1fd172ff3", "status": "affected", "versionType": "git"}, {"version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "lessThan": "e89318aa8629969e86548b05e7c19283af3f0efb", "status": "affected", "versionType": "git"}, {"version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "lessThan": "9688a46802939da28f00cb40e8129615d5d4af39", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/pidfs.c"], "versions": [{"version": "6.11", "status": "affected"}, {"version": "0", "lessThan": "6.11", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.12.112"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.18.51"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bac2f1913a216677c2c220d7bb352dd0330065ca"}, {"url": "https://git.kernel.org/stable/c/cf24ce48d60225fdbee68ed2058763a1fd172ff3"}, {"url": "https://git.kernel.org/stable/c/e89318aa8629969e86548b05e7c19283af3f0efb"}, {"url": "https://git.kernel.org/stable/c/9688a46802939da28f00cb40e8129615d5d4af39"}], "title": "pidfd: hold exec_update_lock around namespace ioctl", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/pidfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "bac2f1913a216677c2c220d7bb352dd0330065ca", "status": "affected", "version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "versionType": "git"}, {"lessThan": "cf24ce48d60225fdbee68ed2058763a1fd172ff3", "status": "affected", "version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "versionType": "git"}, {"lessThan": "e89318aa8629969e86548b05e7c19283af3f0efb", "status": "affected", "version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "versionType": "git"}, {"lessThan": "9688a46802939da28f00cb40e8129615d5d4af39", "status": "affected", "version": "5b08bd408534bfb3a7cf5778da5b27d4e4fffe12", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/pidfs.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.11"}, {"lessThan": "6.11", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.112", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.51", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npidfd: hold exec_update_lock around namespace ioctl\n\nThe PIDFD_GET_*_NAMESPACE ioctls in pidfd_ioctl() perform a filesystem\ncredentials ptrace access check before handing out a namespace file\ndescriptor. The accompanying comment states that the code \"mirrors nsfs\nbehavior\", but, unlike the corresponding procfs paths, it does so without\nholding the target task's exec_update_lock.\n\nproc_ns_get_link() and proc_ns_readlink() both take exec_update_lock for\nreading around the ptrace check and the namespace lookup, so that the\ncredentials used for the access decision match those of the task when its\nnamespace is read. Without it, a caller can pass the check against the\ntarget's old credentials and then read the namespace after the target has\nexecve()'d a setuid binary and committed new credentials -- accessing\nnamespace information it should have been denied.\n\nHold exec_update_lock for reading around the ptrace check and the\nnamespace lookup so that pidfd truly mirrors nsfs behavior, as the comment\nalready claims. open_namespace() itself runs outside the lock: once a\nnamespace reference is obtained it carries its own refcount and is opened\nwith the caller's own credentials, so a concurrent execve() on the target\ncan no longer affect the outcome."}], "id": "CVE-2026-89766", "lastModified": "2026-10-19T09:18:19.833", "metrics": {}, "published": "2026-09-11T20:20:07.850", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9688a46802939da28f00cb40e8129615d5d4af39"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bac2f1913a216677c2c220d7bb352dd0330065ca"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cf24ce48d60225fdbee68ed2058763a1fd172ff3"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e89318aa8629969e86548b05e7c19283af3f0efb"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Information disclosure in pidfd namespace handling", "id": "2532287", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532287"}, "csaw": false, "cvss3": {"cvss3_base_score": "2.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N", "status": "draft"}, "cwe": "CWE-367", "details": ["A flaw was found in the Linux kernel. A local attacker could exploit a race condition in the `pidfd` subsystem, specifically within the `PIDFD_GET_*_NAMESPACE` ioctls. This vulnerability occurs because the system does not properly hold a lock (`exec_update_lock`) during credential checks. This allows an attacker to bypass security restrictions and access sensitive namespace information after a target process has changed its privileges, leading to unauthorized information disclosure."], "name": "CVE-2026-89766", "public_date": "2026-09-11T19:47:06Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89766\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89766\nhttps://git.kernel.org/stable/c/9688a46802939da28f00cb40e8129615d5d4af39\nhttps://git.kernel.org/stable/c/cf24ce48d60225fdbee68ed2058763a1fd172ff3\nhttps://git.kernel.org/stable/c/e89318aa8629969e86548b05e7c19283af3f0efb"], "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b08bd408534bfb3a7cf5778da5b27d4e4fffe12,cf24ce48d60225fdbee68ed2058763a1fd172ff3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b08bd408534bfb3a7cf5778da5b27d4e4fffe12,e89318aa8629969e86548b05e7c19283af3f0efb)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b08bd408534bfb3a7cf5778da5b27d4e4fffe12,9688a46802939da28f00cb40e8129615d5d4af39)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[6.11,6.11]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.11)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[6.18.51,6.18.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2.4,7.2.*]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T05:15:06.923575+00:00", "updated": "2026-09-15T20:00:08.093403+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}