Vulnerability-Lookup

GHSA-V79R-CP4C-R8XR

Vulnerability from github – Published: 2026-08-27 06:31 – Updated: 2026-08-27 06:31

Details

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

ovpn: fix NULL dereference when killing missing key

ovpn_crypto_kill_key assumes both crypto slots are populated and dereferences each slot before checking it. That is not guaranteed: a peer can have only one installed key, and the kill path may be asked to remove a key that is not present.

Read each slot once while holding the crypto state lock, check for NULL before looking at key_id, and only replace the slot that actually matches.

Severity

7.5 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-80520"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-26T15:17:05Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: fix NULL dereference when killing missing key\n\novpn_crypto_kill_key assumes both crypto slots are populated and\ndereferences each slot before checking it. That is not guaranteed: a\npeer can have only one installed key, and the kill path may be asked to\nremove a key that is not present.\n\nRead each slot once while holding the crypto state lock, check for NULL\nbefore looking at key_id, and only replace the slot that actually\nmatches.",
  "id": "GHSA-v79r-cp4c-r8xr",
  "modified": "2026-08-27T06:31:31Z",
  "published": "2026-08-27T06:31:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80520"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/41d44ac7a61e2f74453af40d4fe1b82af9ea0ada"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/acf32a5dff082044cf0fd9492f3c10b7357c15ee"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-80520 (GCVE-0-2026-80520)

Vulnerability from cvelistv5 – Published: 2026-08-26 14:37 – Updated: 2026-08-27 05:01

Title

ovpn: fix NULL dereference when killing missing key

Summary

In the Linux kernel, the following vulnerability has been resolved: ovpn: fix NULL dereference when killing missing key ovpn_crypto_kill_key assumes both crypto slots are populated and dereferences each slot before checking it. That is not guaranteed: a peer can have only one installed key, and the kill path may be asked to remove a key that is not present. Read each slot once while holding the crypto state lock, check for NULL before looking at key_id, and only replace the slot that actually matches.

Severity

7.5 (High)


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

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/a47a080d06ee9d94d…
https://git.kernel.org/stable/c/acf32a5dff082044c…
https://git.kernel.org/stable/c/41d44ac7a61e2f744…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3 (git) Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < acf32a5dff082044cf0fd9492f3c10b7357c15ee (git) Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < 41d44ac7a61e2f74453af40d4fe1b82af9ea0ada (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.46 , ≤ 6.18.* (semver) Unaffected: 7.1.10 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/crypto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3",
              "status": "affected",
              "version": "89d3c0e4612afa1c6429ed68d298e35592fbe208",
              "versionType": "git"
            },
            {
              "lessThan": "acf32a5dff082044cf0fd9492f3c10b7357c15ee",
              "status": "affected",
              "version": "89d3c0e4612afa1c6429ed68d298e35592fbe208",
              "versionType": "git"
            },
            {
              "lessThan": "41d44ac7a61e2f74453af40d4fe1b82af9ea0ada",
              "status": "affected",
              "version": "89d3c0e4612afa1c6429ed68d298e35592fbe208",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/crypto.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.46",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.46",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.10",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: fix NULL dereference when killing missing key\n\novpn_crypto_kill_key assumes both crypto slots are populated and\ndereferences each slot before checking it. That is not guaranteed: a\npeer can have only one installed key, and the kill path may be asked to\nremove a key that is not present.\n\nRead each slot once while holding the crypto state lock, check for NULL\nbefore looking at key_id, and only replace the slot that actually\nmatches."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is reached from ovpn_encrypt_post during outbound VPN encryption over UDP/TCP; a remote authenticated OpenVPN peer can drive high-volume tunnel traffic that exhausts packet IDs and triggers ovpn_crypto_kill_key on internet-facing VPN concentrators.\nAC:L - After a normal rekey leaves one key in slots[1] with slots[0] NULL, IV exhaustion deterministically calls ovpn_crypto_kill_key and the NULL dereference is reliable; a remote peer can sustain the encrypted traffic needed to reach the 32-bit packet-ID limit.\nPR:N - Exploitation requires only an established OpenVPN data-channel session to an ovpn-offloaded interface, not local shell access, CAP_NET_ADMIN, or init-namespace root; no kernel configuration privileges are needed beyond being a connected VPN peer.\nUI:N - Triggering IV exhaustion and the subsequent key-kill path requires no victim user interaction beyond routine automated VPN traffic and key rotation already performed by the tunnel daemon.\nS:U - Impact is a kernel NULL-pointer fault and denial of service within the kernel network stack; it does not cross a security boundary such as guest-to-host escape or sandbox breakout.\nC:N - This is a pure NULL pointer dereference when reading key_id from an unpopulated crypto slot; it does not expose kernel memory, leak pointers, or provide an arbitrary read primitive.\nI:N - The fault occurs on a NULL slot lookup and does not corrupt memory or enable arbitrary writes, code execution, or control-flow hijacking beyond the immediate crash.\nA:H - The NULL dereference in ovpn_crypto_kill_key causes a kernel oops or panic when IV exhaustion triggers the key-kill path, fully denying service to the host and all VPN peers on that node."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-27T05:01:16.637Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3"
        },
        {
          "url": "https://git.kernel.org/stable/c/acf32a5dff082044cf0fd9492f3c10b7357c15ee"
        },
        {
          "url": "https://git.kernel.org/stable/c/41d44ac7a61e2f74453af40d4fe1b82af9ea0ada"
        }
      ],
      "title": "ovpn: fix NULL dereference when killing missing key",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80520",
    "datePublished": "2026-08-26T14:37:01.983Z",
    "dateReserved": "2026-08-26T14:34:25.763Z",
    "dateUpdated": "2026-08-27T05:01:16.637Z",
    "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.

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GHSA-V79R-CP4C-R8XR

CVE-2026-80520 (GCVE-0-2026-80520)

Tags

Sightings

Nomenclature