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

Vulnerability from cvelistv5 – Published: 2026-08-26 14:37 – Updated: 2026-08-27 05:01
VLAI
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
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3 (git)
Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < acf32a5dff082044cf0fd9492f3c10b7357c15ee (git)
Affected: 89d3c0e4612afa1c6429ed68d298e35592fbe208 , < 41d44ac7a61e2f74453af40d4fe1b82af9ea0ada (git)
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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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Show details on NVD website
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/crypto.c"
          ],
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          "vendor": "Linux",
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              "operator": "OR"
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          "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": [
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            "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"
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          "url": "https://git.kernel.org/stable/c/a47a080d06ee9d94dc6a2da0fc2b9beeeedb92b3"
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        },
        {
          "url": "https://git.kernel.org/stable/c/41d44ac7a61e2f74453af40d4fe1b82af9ea0ada"
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      "title": "ovpn: fix NULL dereference when killing missing key",
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    "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"
  },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-27T10:55:24+00:00",
      "cve": "CVE-2026-80520",
      "id": "CVE-2026-80520",
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      "product_status:known_not_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ovpn: fix NULL dereference when killing missing key",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80520.json",
      "version": "3"
    },
    "suse_vex": {
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      "current_release_date": "2026-08-27T16:47:56Z",
      "cve": "CVE-2026-80520",
      "id": "CVE-2026-80520",
      "initial_release_date": "2026-08-27T00:12:46Z",
      "product_status:known_not_affected": "280",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80520",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80520.json",
      "version": "3"
    }
  }
}



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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

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.


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.