Vulnerability-Lookup

FKIE_CVE-2026-89672

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19

Severity

9.1 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Summary

In the Linux kernel, the following vulnerability has been resolved: nfsd: gate nfs2 setacl by argp->mask The NFSACL v2 SETACL path shares the decoder convention used by its v3 sibling: nfsaclsvc_decode_setaclargs() fills in argp->acl_access only when NFS_ACL is set in the request mask and argp->acl_default only when NFS_DFACL is set, leaving the other pointer NULL because the argument buffer is zeroed up to pc_argzero before decode. nfsacld_proc_setacl() then hands both pointers to set_posix_acl() unconditionally. set_posix_acl(idmap, dentry, type, NULL) is the VFS "remove this ACL type" operation, so an omitted arm is indistinguishable from an explicit request to delete that ACL. A SETACL carrying only NFS_ACL silently strips the directory's default ACL; mask=0 strips both. This is the same defect just fixed in nfsd3_proc_setacl(); apply the same remedy. Gate each set_posix_acl() call on its mask bit and initialize error to 0 so that a request with neither bit set leaves the on-disk ACLs untouched and returns success. The out_drop_lock path and the unconditional posix_acl_release() in nfsaclsvc_release_setacl() already tolerate the skipped arms.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8e4422b05f410f95c51b68a0db4bf1d87f6d22f5
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs2acl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8e4422b05f410f95c51b68a0db4bf1d87f6d22f5",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "e41d173d9dc735cecb15ab7aa63ecab09338f81b",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "f951b22dbeec46f2e0fba81cb80d1b0c686b61eb",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "37eea38e7898538f0ec5f1eb8b18d8646e4be41c",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "a3a7e20ed66d3f04d37883c398da8a113b430769",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs2acl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.13"
            },
            {
              "lessThan": "2.6.13",
              "status": "unaffected",
              "version": "0",
              "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-rc1",
              "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\nnfsd: gate nfs2 setacl by argp-\u003emask\n\nThe NFSACL v2 SETACL path shares the decoder convention used by its\nv3 sibling: nfsaclsvc_decode_setaclargs() fills in argp-\u003eacl_access\nonly when NFS_ACL is set in the request mask and argp-\u003eacl_default\nonly when NFS_DFACL is set, leaving the other pointer NULL because\nthe argument buffer is zeroed up to pc_argzero before decode.\n\nnfsacld_proc_setacl() then hands both pointers to set_posix_acl()\nunconditionally. set_posix_acl(idmap, dentry, type, NULL) is the VFS\n\"remove this ACL type\" operation, so an omitted arm is\nindistinguishable from an explicit request to delete that ACL. A\nSETACL carrying only NFS_ACL silently strips the directory\u0027s default\nACL; mask=0 strips both.\n\nThis is the same defect just fixed in nfsd3_proc_setacl(); apply the\nsame remedy. Gate each set_posix_acl() call on its mask bit and\ninitialize error to 0 so that a request with neither bit set leaves\nthe on-disk ACLs untouched and returns success. The out_drop_lock\npath and the unconditional posix_acl_release() in\nnfsaclsvc_release_setacl() already tolerate the skipped arms."
    }
  ],
  "id": "CVE-2026-89672",
  "lastModified": "2026-09-14T13:19:19.193",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:53.770",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8e4422b05f410f95c51b68a0db4bf1d87f6d22f5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-89672 (GCVE-0-2026-89672)

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

Title

nfsd: gate nfs2 setacl by argp->mask

Summary

Severity

9.1 (Critical)


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

Assigner

Linux mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/8e4422b05f410f95c…
https://git.kernel.org/stable/c/e41d173d9dc735cec…
https://git.kernel.org/stable/c/f951b22dbeec46f2e…
https://git.kernel.org/stable/c/37eea38e7898538f0…
https://git.kernel.org/stable/c/a3a7e20ed66d3f04d…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a257cdd0e2179630d3201c32ba14d7fcb3c3a055 , < 8e4422b05f410f95c51b68a0db4bf1d87f6d22f5 (git) Affected: a257cdd0e2179630d3201c32ba14d7fcb3c3a055 , < e41d173d9dc735cecb15ab7aa63ecab09338f81b (git) Affected: a257cdd0e2179630d3201c32ba14d7fcb3c3a055 , < f951b22dbeec46f2e0fba81cb80d1b0c686b61eb (git) Affected: a257cdd0e2179630d3201c32ba14d7fcb3c3a055 , < 37eea38e7898538f0ec5f1eb8b18d8646e4be41c (git) Affected: a257cdd0e2179630d3201c32ba14d7fcb3c3a055 , < a3a7e20ed66d3f04d37883c398da8a113b430769 (git)
Linux	Linux	Affected: 2.6.13 Unaffected: 0 , < 2.6.13 (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)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs2acl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "8e4422b05f410f95c51b68a0db4bf1d87f6d22f5",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "e41d173d9dc735cecb15ab7aa63ecab09338f81b",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "f951b22dbeec46f2e0fba81cb80d1b0c686b61eb",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "37eea38e7898538f0ec5f1eb8b18d8646e4be41c",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            },
            {
              "lessThan": "a3a7e20ed66d3f04d37883c398da8a113b430769",
              "status": "affected",
              "version": "a257cdd0e2179630d3201c32ba14d7fcb3c3a055",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs2acl.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.13"
            },
            {
              "lessThan": "2.6.13",
              "status": "unaffected",
              "version": "0",
              "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-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.157",
                  "versionStartIncluding": "2.6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.109",
                  "versionStartIncluding": "2.6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.50",
                  "versionStartIncluding": "2.6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.4",
                  "versionStartIncluding": "2.6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "2.6.13",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: gate nfs2 setacl by argp-\u003emask\n\nThe NFSACL v2 SETACL path shares the decoder convention used by its\nv3 sibling: nfsaclsvc_decode_setaclargs() fills in argp-\u003eacl_access\nonly when NFS_ACL is set in the request mask and argp-\u003eacl_default\nonly when NFS_DFACL is set, leaving the other pointer NULL because\nthe argument buffer is zeroed up to pc_argzero before decode.\n\nnfsacld_proc_setacl() then hands both pointers to set_posix_acl()\nunconditionally. set_posix_acl(idmap, dentry, type, NULL) is the VFS\n\"remove this ACL type\" operation, so an omitted arm is\nindistinguishable from an explicit request to delete that ACL. A\nSETACL carrying only NFS_ACL silently strips the directory\u0027s default\nACL; mask=0 strips both.\n\nThis is the same defect just fixed in nfsd3_proc_setacl(); apply the\nsame remedy. Gate each set_posix_acl() call on its mask bit and\ninitialize error to 0 so that a request with neither bit set leaves\nthe on-disk ACLs untouched and returns success. The out_drop_lock\npath and the unconditional posix_acl_release() in\nnfsaclsvc_release_setacl() already tolerate the skipped arms."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The flaw is in nfsd NFSACL v2 SETACL (RPC program 100227, ACLPROC2_SETACL) in nfsacld_proc_setacl(); a remote NFS client reaches it over TCP/UDP 2049 via svc_process to nfsd_dispatch and nfsaclsvc_decode_setaclargs.\nAC:L - The attacker supplies the SETACL mask and filehandle. A request with only NFS_ACL, only NFS_DFACL, or mask=0 leaves the omitted posix_acl pointer NULL (pc_argzero), and set_posix_acl() treats NULL as delete with no race or uninfluencable victim state.\nPR:N - Typical AUTH_SYS nfsd exports do not cryptographically verify RPC credentials; any host allowed by the export can MOUNT/LOOKUP and send SETACL with a spoofed AUTH_UNIX owner uid so nfsd_setuser() and inode_owner_or_capable() succeed without a local account.\nUI:N - The attacking NFS client sends the SETACL RPC itself; no local user or administrator action on the NFS server, such as mounting a filesystem or opening a file, is required at attack time.\nS:U - Unintended set_posix_acl(NULL) only removes POSIX ACL xattrs on the exported filesystem of the nfsd host; impact stays in that kernel/filesystem security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:H - Silently deleting a directory default ACL (SETACL with only NFS_ACL, or mask=0 stripping both) drops inheritance so new files are governed only by mode/umask, allowing a remote client to READ subsequently created data those default ACLs were meant to keep confidential.\nI:H - nfsacld_proc_setacl() calls set_posix_acl(..., NULL) for every ACL type omitted from the mask, which is the VFS delete operation, so an attacker-chosen inode can have its access ACL, default ACL, or both completely removed and later writes those ACLs would have denied.\nA:N - This is an unintended POSIX ACL deletion through the normal set_posix_acl(NULL) remove path; it does not oops, panic, hang, deadlock, or leak memory, so the NFS server and host remain available."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-14T12:01:57.798Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/8e4422b05f410f95c51b68a0db4bf1d87f6d22f5"
        },
        {
          "url": "https://git.kernel.org/stable/c/e41d173d9dc735cecb15ab7aa63ecab09338f81b"
        },
        {
          "url": "https://git.kernel.org/stable/c/f951b22dbeec46f2e0fba81cb80d1b0c686b61eb"
        },
        {
          "url": "https://git.kernel.org/stable/c/37eea38e7898538f0ec5f1eb8b18d8646e4be41c"
        },
        {
          "url": "https://git.kernel.org/stable/c/a3a7e20ed66d3f04d37883c398da8a113b430769"
        }
      ],
      "title": "nfsd: gate nfs2 setacl by argp-\u003emask",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89672",
    "datePublished": "2026-09-11T19:45:57.414Z",
    "dateReserved": "2026-09-11T19:38:34.746Z",
    "dateUpdated": "2026-09-14T12:01:57.798Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.