Vulnerability-Lookup

FKIE_CVE-2026-43091

Vulnerability from fkie_nvd - Published: 2026-05-06 10:16 - Updated: 2026-06-17 10:48

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: xfrm: Wait for RCU readers during policy netns exit xfrm_policy_fini() frees the policy_bydst hash tables after flushing the policy work items and deleting all policies, but it does not wait for concurrent RCU readers to leave their read-side critical sections first. The policy_bydst tables are published via rcu_assign_pointer() and are looked up through rcu_dereference_check(), so netns teardown must also wait for an RCU grace period before freeing the table memory. Fix this by adding synchronize_rcu() before freeing the policy hash tables.

References

URL	Tags
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/33a3149dd81a1e2f52b80ee1e0fc380b39f3d028	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3733fce2871c9bca9dd18a1a23b1432ea215a094	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/438b1f668ad58f46ce699bb48e4698a7839e3f9e	Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b66920a3348c0f63ba18365248fa21fbf0b3a937	Patch

Impacted products

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

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_policy.c"
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      "lang": "en",
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    }
  ],
  "id": "CVE-2026-43091",
  "lastModified": "2026-06-17T10:48:55.183",
  "metrics": {
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        "cvssData": {
          "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"
      }
    ]
  },
  "published": "2026-05-06T10:16:22.433",
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446"
    },
    {
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  "vulnStatus": "Analyzed",
  "weaknesses": [
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        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}

CVE-2026-43091 (GCVE-0-2026-43091)

Vulnerability from cvelistv5 – Published: 2026-05-06 07:40 – Updated: 2026-08-05 12:25

Title

xfrm: Wait for RCU readers during policy netns exit

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 mitre root

References

5 references

URL	Tags
https://git.kernel.org/stable/c/b66920a3348c0f63b…
https://git.kernel.org/stable/c/438b1f668ad58f46c…
https://git.kernel.org/stable/c/3733fce2871c9bca9…
https://git.kernel.org/stable/c/33a3149dd81a1e2f5…
https://git.kernel.org/stable/c/069daad4f2ae9c5c1…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: e1e551bc56302b80ff930c966f9985095fb1b70d , < b66920a3348c0f63ba18365248fa21fbf0b3a937 (git) Affected: e1e551bc56302b80ff930c966f9985095fb1b70d , < 438b1f668ad58f46ce699bb48e4698a7839e3f9e (git) Affected: e1e551bc56302b80ff930c966f9985095fb1b70d , < 3733fce2871c9bca9dd18a1a23b1432ea215a094 (git) Affected: e1e551bc56302b80ff930c966f9985095fb1b70d , < 33a3149dd81a1e2f52b80ee1e0fc380b39f3d028 (git) Affected: e1e551bc56302b80ff930c966f9985095fb1b70d , < 069daad4f2ae9c5c108131995529d5f02392c446 (git)
Linux	Linux	Affected: 4.9 Unaffected: 0 , < 4.9 (semver) Unaffected: 6.6.136 , ≤ 6.6.* (semver) Unaffected: 6.12.83 , ≤ 6.12.* (semver) Unaffected: 6.18.24 , ≤ 6.18.* (semver) Unaffected: 6.19.14 , ≤ 6.19.* (semver) Unaffected: 7.0 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/xfrm/xfrm_policy.c"
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          "versions": [
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            }
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      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:25:52.160Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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        },
        {
          "url": "https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446"
        }
      ],
      "title": "xfrm: Wait for RCU readers during policy netns exit",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-43091",
    "datePublished": "2026-05-06T07:40:23.955Z",
    "dateReserved": "2026-05-01T14:12:55.984Z",
    "dateUpdated": "2026-08-05T12:25:52.160Z",
    "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.