Vulnerability-Lookup

FKIE_CVE-2026-43374

Vulnerability from fkie_nvd - Published: 2026-05-08 15:16 - Updated: 2026-05-15 15:16

Severity

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

Summary

In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix percpu use-after-free in remove_nh_grp_entry When removing a nexthop from a group, remove_nh_grp_entry() publishes the new group via rcu_assign_pointer() then immediately frees the removed entry's percpu stats with free_percpu(). However, the synchronize_net() grace period in the caller remove_nexthop_from_groups() runs after the free. RCU readers that entered before the publish still see the old group and can dereference the freed stats via nh_grp_entry_stats_inc() -> get_cpu_ptr(nhge->stats), causing a use-after-free on percpu memory. Fix by deferring the free_percpu() until after synchronize_net() in the caller. Removed entries are chained via nh_list onto a local deferred free list. After the grace period completes and all RCU readers have finished, the percpu stats are safely freed.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/9e08ad731862b22a87cc55f752e16d66cdc9e231	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ab5ebab9664214ba41a7633cb4e72f128204f924	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/abf4feaee6405f1441929c6ebe7a250f2cd170a7	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b2662e7593e94ae09b1cf7ee5f09160a3612bcb2	Patch

Impacted products

Vendor	Product	Version
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	*
linux	linux_kernel	6.9
linux	linux_kernel	7.0
linux	linux_kernel	7.0
linux	linux_kernel	7.0

JSON

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{
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: nexthop: fix percpu use-after-free in remove_nh_grp_entry\n\nWhen removing a nexthop from a group, remove_nh_grp_entry() publishes\nthe new group via rcu_assign_pointer() then immediately frees the\nremoved entry\u0027s percpu stats with free_percpu(). However, the\nsynchronize_net() grace period in the caller remove_nexthop_from_groups()\nruns after the free. RCU readers that entered before the publish still\nsee the old group and can dereference the freed stats via\nnh_grp_entry_stats_inc() -\u003e get_cpu_ptr(nhge-\u003estats), causing a\nuse-after-free on percpu memory.\n\nFix by deferring the free_percpu() until after synchronize_net() in the\ncaller. Removed entries are chained via nh_list onto a local deferred\nfree list. After the grace period completes and all RCU readers have\nfinished, the percpu stats are safely freed."
    }
  ],
  "id": "CVE-2026-43374",
  "lastModified": "2026-05-15T15:16:31.143",
  "metrics": {
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          "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"
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-43374 (GCVE-0-2026-43374)

Vulnerability from cvelistv5 – Published: 2026-05-08 14:21 – Updated: 2026-05-11 22:23

Title

net: nexthop: fix percpu use-after-free in remove_nh_grp_entry

Summary

Severity

7.8 (High)


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

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/abf4feaee6405f144…
https://git.kernel.org/stable/c/ab5ebab9664214ba4…
https://git.kernel.org/stable/c/9e08ad731862b22a8…
https://git.kernel.org/stable/c/b2662e7593e94ae09…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f4676ea74b8549cd88dbfe2a592ce4530039e61f , < abf4feaee6405f1441929c6ebe7a250f2cd170a7 (git) Affected: f4676ea74b8549cd88dbfe2a592ce4530039e61f , < ab5ebab9664214ba41a7633cb4e72f128204f924 (git) Affected: f4676ea74b8549cd88dbfe2a592ce4530039e61f , < 9e08ad731862b22a87cc55f752e16d66cdc9e231 (git) Affected: f4676ea74b8549cd88dbfe2a592ce4530039e61f , < b2662e7593e94ae09b1cf7ee5f09160a3612bcb2 (git)
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.12.78 , ≤ 6.12.* (semver) Unaffected: 6.18.19 , ≤ 6.18.* (semver) Unaffected: 6.19.9 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

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          "programFiles": [
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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.

Detection rules are retrieved from Rulezet.

Action not permitted

FKIE_CVE-2026-43374

CVE-2026-43374 (GCVE-0-2026-43374)

Tags

Sightings

Nomenclature