Vulnerability-Lookup

GHSA-M87W-W8MV-RF6C

Vulnerability from github – Published: 2026-09-11 21:31 – Updated: 2026-09-14 15:32

Details

In the Linux kernel, the following vulnerability has been resolved:

ecryptfs: pass packet set buffer size to parser

ecryptfs_parse_packet_set() receives a pointer into the file header, but it calculates the remaining packet buffer size from PAGE_SIZE - 8. For version 1 headers the packet set starts later in the header, so this can overstate the available buffer.

Pass the actual packet set buffer length from the caller and calculate per-packet limits from the remaining bytes in that buffer. Recompute the remaining length after consuming a tag 3 packet before parsing the following tag 11 packet.

Severity

7.1 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89608"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T20:19:45Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: pass packet set buffer size to parser\n\necryptfs_parse_packet_set() receives a pointer into the file header, but\nit calculates the remaining packet buffer size from PAGE_SIZE - 8.  For\nversion 1 headers the packet set starts later in the header, so this can\noverstate the available buffer.\n\nPass the actual packet set buffer length from the caller and calculate\nper-packet limits from the remaining bytes in that buffer.  Recompute the\nremaining length after consuming a tag 3 packet before parsing the\nfollowing tag 11 packet.",
  "id": "GHSA-m87w-w8mv-rf6c",
  "modified": "2026-09-14T15:32:31Z",
  "published": "2026-09-11T21:31:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89608"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/329de8b9e988b152b938f09224670d97bada0b96"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3bd9bb3e167a7c14a50423f6ff03ee0fb007199d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/66a87559ecb26afe80ad512faf728a158e2b81da"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/747fd45be396a6aea3420ab657a0ab4e60185b05"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/749fa08d8f1b318bd8f4669a14a8a4a8c1bbdaac"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e5d254e654f2311a3c4b9c791d7f216554bcd17a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e7573b0e3058c6bbdfe81673f22c09900fde9e65"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89608 (GCVE-0-2026-89608)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:45 – Updated: 2026-09-14 12:01

Title

ecryptfs: pass packet set buffer size to parser

Summary

In the Linux kernel, the following vulnerability has been resolved: ecryptfs: pass packet set buffer size to parser ecryptfs_parse_packet_set() receives a pointer into the file header, but it calculates the remaining packet buffer size from PAGE_SIZE - 8. For version 1 headers the packet set starts later in the header, so this can overstate the available buffer. Pass the actual packet set buffer length from the caller and calculate per-packet limits from the remaining bytes in that buffer. Recompute the remaining length after consuming a tag 3 packet before parsing the following tag 11 packet.

Severity

7.1 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/e7573b0e3058c6bbd…
https://git.kernel.org/stable/c/66a87559ecb26afe8…
https://git.kernel.org/stable/c/3bd9bb3e167a7c14a…
https://git.kernel.org/stable/c/749fa08d8f1b318bd…
https://git.kernel.org/stable/c/329de8b9e988b152b…
https://git.kernel.org/stable/c/e5d254e654f2311a3…
https://git.kernel.org/stable/c/747fd45be396a6aea…
https://git.kernel.org/stable/c/2602b79c5b3e2f6fc…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < e7573b0e3058c6bbdfe81673f22c09900fde9e65 (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 66a87559ecb26afe80ad512faf728a158e2b81da (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 3bd9bb3e167a7c14a50423f6ff03ee0fb007199d (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 749fa08d8f1b318bd8f4669a14a8a4a8c1bbdaac (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 329de8b9e988b152b938f09224670d97bada0b96 (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < e5d254e654f2311a3c4b9c791d7f216554bcd17a (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 747fd45be396a6aea3420ab657a0ab4e60185b05 (git) Affected: 237fead619984cc48818fe12ee0ceada3f55b012 , < 2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2 (git)
Linux	Linux	Affected: 2.6.19 Unaffected: 0 , < 2.6.19 (semver) Unaffected: 5.10.270 , ≤ 5.10.* (semver) Unaffected: 5.15.221 , ≤ 5.15.* (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.109 , ≤ 6.12.* (semver) Unaffected: 6.18.50 , ≤ 6.18.* (semver) Unaffected: 7.2.4 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
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        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/ecryptfs/crypto.c",
            "fs/ecryptfs/ecryptfs_kernel.h",
            "fs/ecryptfs/keystore.c"
          ],
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              "version": "0",
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              "status": "unaffected",
              "version": "5.10.270",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "5.15.221",
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              "status": "unaffected",
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                {
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                {
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                {
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                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "2.6.19",
                  "vulnerable": true
                }
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        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: pass packet set buffer size to parser\n\necryptfs_parse_packet_set() receives a pointer into the file header, but\nit calculates the remaining packet buffer size from PAGE_SIZE - 8.  For\nversion 1 headers the packet set starts later in the header, so this can\noverstate the available buffer.\n\nPass the actual packet set buffer length from the caller and calculate\nper-packet limits from the remaining bytes in that buffer.  Recompute the\nremaining length after consuming a tag 3 packet before parsing the\nfollowing tag 11 packet."
        }
      ],
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            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The over-read is reached only by a local open or setattr on an eCryptfs mount (ecryptfs_open/ecryptfs_setattr \u2192 ecryptfs_read_metadata \u2192 ecryptfs_parse_packet_set) which parses the attacker-supplied lower-file header or xattr; this is not a network protocol path.\nAC:L - Opening a crafted eCryptfs file deterministically feeds attacker-controlled version-1 headers and Tag 1/3/11 lengths into parse_packet_set(), which then uses an overstated PAGE_SIZE-8 bound; no race or uninfluenced memory layout is required.\nPR:L - An unprivileged user reaches this on standard eCryptfs deployments (setuid-root mount.ecryptfs_private and per-user encrypted home/Private) by planting a crafted file in their own lower directory and opening it through the already-mounted tree; init-namespace root is not required.\nUI:N - The attacker writes the malformed header into their lower directory and opens the corresponding eCryptfs file themselves; no action by another user is required.\nS:U - The out-of-bounds header-slab read and any resulting oops stay inside the host kernel eCryptfs code; this is not a VM escape, IOMMU bypass, or other cross-authority breakout.\nC:H - parse_packet_set() treats PAGE_SIZE-8 as the packet-set limit even after the version-1 header advances the pointer, and Tag 11 is parsed with the pre-Tag-3 remainder so max_packet_size can underflow; subsequent Tag 1 copies up to 512 bytes from adjacent slab/pages, an OOB read rated High unless a few bytes.\nI:N - Packet parsers memcpy into size-checked destinations (encrypted_key[], sig_tmp_space[8]); this bug is a source over-read of the PAGE_SIZE header cache object, not an out-of-bounds write, UAF, or control-flow hijack primitive.\nA:H - After the size_t remainder underflows, src[i] and later memcpy() walk off the header cache object into adjacent or unmapped pages and can oops; the attacker can reopen the crafted file to crash the host at will."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T12:01:28.889Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
          "url": "https://git.kernel.org/stable/c/747fd45be396a6aea3420ab657a0ab4e60185b05"
        },
        {
          "url": "https://git.kernel.org/stable/c/2602b79c5b3e2f6fce12e38a670f8e3fda4e46a2"
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      ],
      "title": "ecryptfs: pass packet set buffer size to parser",
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        "engine": "bippy-1.2.0"
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89608",
    "datePublished": "2026-09-11T19:45:10.318Z",
    "dateReserved": "2026-09-11T19:38:34.733Z",
    "dateUpdated": "2026-09-14T12:01:28.889Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-M87W-W8MV-RF6C

CVE-2026-89608 (GCVE-0-2026-89608)

Tags

Sightings

Nomenclature