{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.177-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.95-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.3-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  mac802154: llsec: add skb_cow_data() before in-place crypto  llsec_do_encrypt_unauth(), llsec_do_encrypt_auth(), llsec_do_decrypt_unauth(), and llsec_do_decrypt_auth() all perform in-place cryptographic transformations on skb data.  They build a scatterlist with sg_init_one() pointing into the skb's linear data area and then pass the same scatterlist as both src and dst to the crypto API (e.g. crypto_skcipher_encrypt/decrypt, crypto_aead_encrypt/decrypt).  On the RX path, __ieee802154_rx_handle_packet() clones the received skb before handing it to each subscriber via ieee802154_subif_frame().  The cloned skb shares the same underlying data buffer via reference counting.  When llsec_do_decrypt() subsequently modifies this shared buffer in place, it corrupts data that other clones -- potentially belonging to other sockets or subsystems -- still reference.  On the TX path, similar data sharing can occur when an skb's head has been cloned (skb_cloned() returns true).  The fix is to call skb_cow_data() before performing any in-place crypto operation.  skb_cow_data() ensures that the skb's data area is not shared: if the skb head is cloned or the data spans multiple fragments, it copies the data into a private buffer that can be safely modified in place.  This is the same pattern used by:    - ESP (net/ipv4/esp4.c, net/ipv6/esp6.c)   - MACsec (drivers/net/macsec.c)   - WireGuard (drivers/net/wireguard/receive.c)   - TIPC (net/tipc/crypto.c)  Without this guard, in-place crypto on shared skb data leads to:   - Silent data corruption of other skb clones   - Use-after-free when the crypto API scatterwalk writes through a     page that has already been freed by another clone's kfree_skb()   - Kernel crashes under concurrent 802.15.4 traffic with security     enabled (KASAN/KMSAN reports slab-use-after-free)  Found by 0sec (https://0sec.ai) using automated source analysis.",
  "id": "DEBIAN-CVE-2026-63831",
  "modified": "2026-09-14T16:47:40.912054262Z",
  "published": "2026-07-19T12:16:56.460Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-63831"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-63831"
  ]
}