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CVE-2026-89700 (GCVE-0-2026-89700)

Vulnerability from cvelistv5 – Published: 2026-09-11 19:46 – Updated: 2026-09-11 19:46
VLAI
Title
nfsd: validate sockaddr length per family in listener_set
Summary
In the Linux kernel, the following vulnerability has been resolved: nfsd: validate sockaddr length per family in listener_set nfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY attribute with no minimum length. A CAP_NET_ADMIN caller can send a 16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte OOB read across three consumers (rpc_cmp_addr_port, svc_find_listener, kernel_bind). nfsd_nl_listener_set_doit() also parsed and validated each listener entry inline in two separate loops, interleaved with mutating the running listener configuration. The validation was duplicated, used an open-coded "nla_len < sizeof(struct sockaddr)" check that was too short for AF_INET6, and handled a malformed entry inconsistently depending on which loop noticed it. Add an nfsd_nl_validate_listeners() helper that walks the entire list once and confirms each entry parses, carries both an address and a transport name, and is long enough for its address family (sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6) for AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking nfsd_mutex or creating the serv, so a malformed request fails cleanly with no side effects. Since every entry is known valid by the time the two existing loops run, drop the redundant presence and per-family length checks from both, leaving only the nla_parse_nested() call needed to extract the data.
Severity
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 16a471177496c8e04a9793812c187a2c1a2192fa , < 2aca70c18c5f5d06004122861fb151d5fcc57faf (git)
Affected: 16a471177496c8e04a9793812c187a2c1a2192fa , < 22d0e4752ca88fd84196d22ebeedc905e6540440 (git)
Affected: 16a471177496c8e04a9793812c187a2c1a2192fa , < bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464 (git)
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Linux Linux Affected: 6.10
Unaffected: 0 , < 6.10 (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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{
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          "product": "Linux",
          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: validate sockaddr length per family in listener_set\n\nnfsd_sock_nl_policy declares NFSD_A_SOCK_ADDR as a bare NLA_BINARY\nattribute with no minimum length. A CAP_NET_ADMIN caller can send a\n16-byte NFSD_A_SOCK_ADDR with sa_family=AF_INET6, causing a 12-byte\nOOB read across three consumers (rpc_cmp_addr_port, svc_find_listener,\nkernel_bind).\n\nnfsd_nl_listener_set_doit() also parsed and validated each listener\nentry inline in two separate loops, interleaved with mutating the\nrunning listener configuration. The validation was duplicated, used an\nopen-coded \"nla_len \u003c sizeof(struct sockaddr)\" check that was too short\nfor AF_INET6, and handled a malformed entry inconsistently depending on\nwhich loop noticed it.\n\nAdd an nfsd_nl_validate_listeners() helper that walks the entire list\nonce and confirms each entry parses, carries both an address and a\ntransport name, and is long enough for its address family\n(sizeof(struct sockaddr_in) for AF_INET, sizeof(struct sockaddr_in6)\nfor AF_INET6, -EAFNOSUPPORT otherwise). Call it before taking\nnfsd_mutex or creating the serv, so a malformed request fails cleanly\nwith no side effects.\n\nSince every entry is known valid by the time the two existing loops\nrun, drop the redundant presence and per-family length checks from\nboth, leaving only the nla_parse_nested() call needed to extract the\ndata."
        }
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        "dateUpdated": "2026-09-11T19:46:18.076Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/2aca70c18c5f5d06004122861fb151d5fcc57faf"
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        {
          "url": "https://git.kernel.org/stable/c/bdcc85c2b05a9378d8bd2d65f9fc41440a3cf464"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89700",
    "datePublished": "2026-09-11T19:46:18.076Z",
    "dateReserved": "2026-09-11T19:38:34.750Z",
    "dateUpdated": "2026-09-11T19:46:18.076Z",
    "state": "PUBLISHED"
  },
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      "cve": "CVE-2026-89700",
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      "title": "kernel: Linux kernel nfsd: Out-of-bounds read due to improper sockaddr length validation",
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      "cve": "CVE-2026-89700",
      "id": "CVE-2026-89700",
      "initial_release_date": "2026-09-12T16:23:25Z",
      "product_status:known_affected": "29",
      "product_status:known_not_affected": "324",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-89700",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-89700.json",
      "version": "4"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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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.


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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.