CVE-2026-89606

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89606", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.733Z", "datePublished": "2026-09-11T19:45:08.832Z", "dateUpdated": "2026-10-19T08:49:37.417Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:49:37.417Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: reject too-small tag 70 packets\n\necryptfs_parse_tag_70_packet() subtracts fixed metadata fields from the\nparsed packet body size to derive the encrypted filename size. A\nmalformed packet with a body smaller than those fixed fields can underflow\nthat size calculation.\n\nReject tag 70 packets before the subtraction unless the body contains the\nsignature, cipher code, and at least one byte of encrypted filename data."}], "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 bug is reached only through local VFS operations on an eCryptfs mount with filename encryption: getdents via ecryptfs_filldir() and readlink via ecryptfs_get_link(), which decode lower-filesystem names or symlink targets into tag 70 packets. No network protocol or remote peer data is parsed.\nAC:L - An attacker who can create names on the lower filesystem fully controls the tag-70 length byte and can copy a valid FNEK signature from their own mount or existing encrypted names, so the unsigned size wrap is deterministic with no race or uninfluenced condition.\nPR:L - Unprivileged users reach this on standard eCryptfs deployments (encrypted home/Private via setuid mount.ecryptfs_private, or an already-mounted per-user eCryptfs directory) by writing the lower directory they own; triggering does not require init-namespace root.\nUI:N - The attacker plants the malformed ECRYPTFS_FNEK_ENCRYPTED name or lower symlink target and then issues getdents or readlink on their own eCryptfs mount; no separate victim action is required, and in the encrypted-home case the mount already exists at login.\nS:U - Memory corruption and oops stay inside the host kernel's eCryptfs/VFS context. This is ordinary kernel impact, not a VM, IOMMU, or sandbox-boundary escape.\nC:H - The underflowed block_aligned_filename_size is used as the scatterlist, kmalloc, and skcipher-decrypt length for the encrypted filename, so a wrapped length becomes an out-of-bounds read of kernel memory adjacent to the decoded packet buffer.\nI:H - The same wrapped length is the destination size for kmalloc plus crypto_skcipher_decrypt and the subsequent memcpy of the decrypted name, yielding an out-of-bounds write into heap/crypto scratch buffers that can be used for control-flow hijack.\nA:H - virt_to_scatterlist() returns 0 for the wrapped size without the caller setting rc, so parse_tag_70_packet() returns success with a NULL filename; ecryptfs_get_link() then does buf[len]='\\0' on that NULL pointer and oopses the kernel."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", 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{"version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "lessThan": "d2869768eab5648e6edc05f47e0716e5328e6681", "status": "affected", "versionType": "git"}, {"version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "lessThan": "e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f", "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/ecryptfs/keystore.c"], "versions": [{"version": "2.6.29", "status": "affected"}, {"version": "0", "lessThan": "2.6.29", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.270", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.221", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.188", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "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": "2.6.29", "versionEndExcluding": "5.10.270"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": "5.15.221"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.29", "versionEndExcluding": 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"https://git.kernel.org/stable/c/2e5afed9503dd1d85004c09503adc2cb584c0188"}, {"url": "https://git.kernel.org/stable/c/414a0f04feb06f03523edf7e2a8be1d7f1a9b160"}, {"url": "https://git.kernel.org/stable/c/9d88391bbed76eb091cddd50b0af87b1c6f22589"}, {"url": "https://git.kernel.org/stable/c/b31da1ecf13929a8d7f8d2727843d2fe35396b75"}, {"url": "https://git.kernel.org/stable/c/d2869768eab5648e6edc05f47e0716e5328e6681"}, {"url": "https://git.kernel.org/stable/c/e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f"}], "title": "ecryptfs: reject too-small tag 70 packets", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["fs/ecryptfs/keystore.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "df5f375a6151ef71f636da044bcef90c26697255", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "5668121974eb7f7aa82793a9d0d13abadb8904dc", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "2e5afed9503dd1d85004c09503adc2cb584c0188", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "414a0f04feb06f03523edf7e2a8be1d7f1a9b160", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "9d88391bbed76eb091cddd50b0af87b1c6f22589", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "b31da1ecf13929a8d7f8d2727843d2fe35396b75", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "d2869768eab5648e6edc05f47e0716e5328e6681", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}, {"lessThan": "e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f", "status": "affected", "version": "9c79f34f7ee71cd28272332b424ca64b2be006ab", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["fs/ecryptfs/keystore.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "2.6.29"}, {"lessThan": "2.6.29", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "5.10.*", "status": "unaffected", "version": "5.10.270", "versionType": "semver"}, {"lessThanOrEqual": "5.15.*", "status": "unaffected", "version": "5.15.221", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.188", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.157", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "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\necryptfs: reject too-small tag 70 packets\n\necryptfs_parse_tag_70_packet() subtracts fixed metadata fields from the\nparsed packet body size to derive the encrypted filename size. A\nmalformed packet with a body smaller than those fixed fields can underflow\nthat size calculation.\n\nReject tag 70 packets before the subtraction unless the body contains the\nsignature, cipher code, and at least one byte of encrypted filename data."}], "id": "CVE-2026-89606", "lastModified": "2026-10-19T09:17:57.093", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}]}, "published": "2026-09-11T20:19:45.603", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2e5afed9503dd1d85004c09503adc2cb584c0188"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/414a0f04feb06f03523edf7e2a8be1d7f1a9b160"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5668121974eb7f7aa82793a9d0d13abadb8904dc"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9d88391bbed76eb091cddd50b0af87b1c6f22589"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b31da1ecf13929a8d7f8d2727843d2fe35396b75"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/d2869768eab5648e6edc05f47e0716e5328e6681"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/df5f375a6151ef71f636da044bcef90c26697255"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: ecryptfs: Denial of Service via malformed tag 70 packets", "id": "2532266", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532266"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-191", "details": ["A flaw was found in ecryptfs, a component of the Linux kernel. This vulnerability allows a remote attacker to send a specially crafted tag 70 packet with a body smaller than expected. This can lead to an integer underflow during size calculation, potentially causing a denial of service (DoS) or system instability."], "name": "CVE-2026-89606", "public_date": "2026-09-11T19:45:08Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89606\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89606\nhttps://git.kernel.org/stable/c/9d88391bbed76eb091cddd50b0af87b1c6f22589\nhttps://git.kernel.org/stable/c/b31da1ecf13929a8d7f8d2727843d2fe35396b75\nhttps://git.kernel.org/stable/c/d2869768eab5648e6edc05f47e0716e5328e6681\nhttps://git.kernel.org/stable/c/e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9c79f34f7ee71cd28272332b424ca64b2be006ab,9d88391bbed76eb091cddd50b0af87b1c6f22589)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9c79f34f7ee71cd28272332b424ca64b2be006ab,b31da1ecf13929a8d7f8d2727843d2fe35396b75)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9c79f34f7ee71cd28272332b424ca64b2be006ab,d2869768eab5648e6edc05f47e0716e5328e6681)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[9c79f34f7ee71cd28272332b424ca64b2be006ab,e97bbe1b2bd82ec2ae37ad2e4965b4d3e78bbf7f)"}}], "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": "2.6.29"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,2.6.29)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"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": "2026-09-12T06:45:10.801862+00:00", "updated": "2026-09-15T21:45:17.655316+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}