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GHSA-WRFX-CH9C-5JJ2

Vulnerability from github – Published: 2026-10-23 15:31 – Updated: 2026-10-23 15:31

Details

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

ipv4: stop route notification sizing when nexthop group shrinks

Commit 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") added an RCU-only fib_nlmsg_size() call for asynchronous hardware flag notifications.

fib_nlmsg_size() checks fib_info_num_path() before each iteration, then fib_info_nhc() independently reloads nh->nh_grp. If RTM_NEWNEXTHOP replaces a group with fewer paths between those loads, fib_info_nhc() returns NULL and fib_nexthop_nlmsg_size() dereferences it.

Stop sizing when the indexed path is absent. Nexthop groups are dense, so the current snapshot has no later path.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-99072"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-23T13:17:31Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv4: stop route notification sizing when nexthop group shrinks\n\nCommit 680aea08e78c (\"net: ipv4: Emit notification when fib\nhardware flags are changed\") added an RCU-only fib_nlmsg_size() call\nfor asynchronous hardware flag notifications.\n\nfib_nlmsg_size() checks fib_info_num_path() before each iteration,\nthen fib_info_nhc() independently reloads nh-\u003enh_grp. If\nRTM_NEWNEXTHOP replaces a group with fewer paths between those loads,\nfib_info_nhc() returns NULL and fib_nexthop_nlmsg_size() dereferences\nit.\n\nStop sizing when the indexed path is absent. Nexthop groups are\ndense, so the current snapshot has no later path.",
  "id": "GHSA-wrfx-ch9c-5jj2",
  "modified": "2026-10-23T15:31:37Z",
  "published": "2026-10-23T15:31:37Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-99072"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/72d9d17092bb37b0717f12042a0817d01a1f9e78"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad1c9f1b98c92609e9bb2ae8f05916defc3b0a54"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad2b3a68b8a7d5d27de88e05674e4adb1ce46d88"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1f48d1c2d5e9efd904dbbc2f2b3d41543e55c49"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d3daa33c7af92e38f2274bbd2576f58bfbaf89e6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-99072 (GCVE-0-2026-99072)

Vulnerability from cvelistv5 – Published: 2026-10-23 12:23 – Updated: 2026-10-23 12:23

Title

ipv4: stop route notification sizing when nexthop group shrinks

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv4: stop route notification sizing when nexthop group shrinks Commit 680aea08e78c ("net: ipv4: Emit notification when fib hardware flags are changed") added an RCU-only fib_nlmsg_size() call for asynchronous hardware flag notifications. fib_nlmsg_size() checks fib_info_num_path() before each iteration, then fib_info_nhc() independently reloads nh->nh_grp. If RTM_NEWNEXTHOP replaces a group with fewer paths between those loads, fib_info_nhc() returns NULL and fib_nexthop_nlmsg_size() dereferences it. Stop sizing when the indexed path is absent. Nexthop groups are dense, so the current snapshot has no later path.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7067 records in the last 180 days details

References

5 references

URL	Tags
https://git.kernel.org/stable/c/72d9d17092bb37b07…
https://git.kernel.org/stable/c/ad1c9f1b98c92609e…
https://git.kernel.org/stable/c/c1f48d1c2d5e9efd9…
https://git.kernel.org/stable/c/ad2b3a68b8a7d5d27…
https://git.kernel.org/stable/c/d3daa33c7af92e38f…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 680aea08e78c003292415518ad270bc20f9c80b1 , < 72d9d17092bb37b0717f12042a0817d01a1f9e78 (git) Affected: 680aea08e78c003292415518ad270bc20f9c80b1 , < ad1c9f1b98c92609e9bb2ae8f05916defc3b0a54 (git) Affected: 680aea08e78c003292415518ad270bc20f9c80b1 , < c1f48d1c2d5e9efd904dbbc2f2b3d41543e55c49 (git) Affected: 680aea08e78c003292415518ad270bc20f9c80b1 , < ad2b3a68b8a7d5d27de88e05674e4adb1ce46d88 (git) Affected: 680aea08e78c003292415518ad270bc20f9c80b1 , < d3daa33c7af92e38f2274bbd2576f58bfbaf89e6 (git)
Linux	Linux	Affected: 5.12 Unaffected: 0 , < 5.12 (semver) Unaffected: 6.6.160 , ≤ 6.6.* (semver) Unaffected: 6.12.113 , ≤ 6.12.* (semver) Unaffected: 6.18.57 , ≤ 6.18.* (semver) Unaffected: 7.2.11 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

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{
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        {
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          "programFiles": [
            "net/ipv4/fib_semantics.c"
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              "versionType": "semver"
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              "status": "unaffected",
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}

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.

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