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CVE-2026-45929

Estado: En análisisAlta (7.8)—

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

ovpn: fix possible use-after-free in ovpn_net_xmit

When building the skb_list in ovpn_net_xmit, skb_share_check will free the original skb if it is shared. The current implementation continues to use the stale skb pointer for subsequent operations: - peer lookup, - skb_dst_drop (even though all segments produced by skb_gso_segment will have a dst attached), - ovpn_peer_stats_increment_tx.

Fix this by moving the peer lookup and skb_dst_drop before segmentation so that the original skb is still valid when used. Return early if all segments fail skb_share_check and the list ends up empty. Also switch ovpn_peer_stats_increment_tx to use skb_list.next; the next patch fixes the stats logic.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Acceso local con PR:L y vulnerabilidad de use-after-free (CWE-416) en kernel. La pista sugiere T1068 e impacto en ejecución de código. Sin exploración de privilegios explícita, se asume escalada local mediante manipulación de memoria en el kernel.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Execution PreventionThreat Intelligence ProgramRestrict Web-Based ContentPrivileged Account ManagementLimit Software InstallationBehavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

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  "id": "CVE-2026-45929",
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          "version": "3.1",
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          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
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          "confidentialityImpact": "HIGH"
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  "published": "2026-05-27T14:17:08.833",
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      "tags": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  "vulnStatus": "Undergoing Analysis",
  "weaknesses": [
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      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
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          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: fix possible use-after-free in ovpn_net_xmit\n\nWhen building the skb_list in ovpn_net_xmit, skb_share_check will free\nthe original skb if it is shared. The current implementation continues\nto use the stale skb pointer for subsequent operations:\n- peer lookup,\n- skb_dst_drop (even though all segments produced by skb_gso_segment\n  will have a dst attached),\n- ovpn_peer_stats_increment_tx.\n\nFix this by moving the peer lookup and skb_dst_drop before segmentation\nso that the original skb is still valid when used. Return early if all\nsegments fail skb_share_check and the list ends up empty.\nAlso switch ovpn_peer_stats_increment_tx to use skb_list.next; the next\npatch fixes the stats logic."
    }
  ],
  "lastModified": "2026-06-25T12:43:33.257",
  "configurations": [
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}