{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  sctp: fix NULL deref on untransmitted RECONF completion  sctp_process_strreset_outreq(), sctp_process_strreset_addstrm_out() and sctp_process_strreset_resp() complete a pending stream reconfiguration request by stopping the reconf timer on the transport it was sent on:  \tt = asoc-\u003estrreset_chunk-\u003etransport; \tif (timer_delete(\u0026t-\u003ereconf_timer)) \t\tsctp_transport_put(t);  chunk-\u003etransport is assigned by __sctp_packet_append_chunk() when the chunk is appended to an outbound packet, and sctp_outq_flush_ctrl() arms the reconf timer at that same point. A request already published in asoc-\u003estrreset_chunk but not yet transmitted has neither, so completing it dereferences NULL.  Two ways to get there. sctp_send_asconf_del_ip() sets asoc-\u003esrc_out_of_asoc_ok without sending anything when the address being removed is the association's last one, and sctp_outq_flush_ctrl() then leaves every non-ASCONF control chunk queued; as only sctp_process_asconf_ack() clears that flag, it persists. An unprivileged process that removes such an address and then asks for a stream reset panics the kernel from softirq. A peer needs neither ASCONF nor local help: sctp_cmd_interpreter() uncorks the outqueue only once the whole packet has been processed, so a reply built while walking a RECONF chunk stays untransmitted for the rest of that walk, and one RECONF chunk carrying [Incoming SSN Reset Request, Outgoing SSN Reset Request, Response] -- or two RECONF chunks in one packet -- reaches the same dereference.    KASAN: null-ptr-deref in range [0x00000000000001e8-0x00000000000001ef]   RIP: 0010:timer_delete+0x67/0x110   Call Trace:    \u003cIRQ\u003e    sctp_process_strreset_addstrm_out (net/sctp/stream.c:832)    sctp_sf_do_reconf (net/sctp/sm_statefuns.c:4212)    sctp_do_sm (net/sctp/sm_sideeffect.c:1172)    sctp_assoc_bh_rcv (net/sctp/associola.c:1044)    sctp_rcv (net/sctp/input.c:243)    ip_local_deliver (net/ipv4/ip_input.c:262)    process_backlog (net/core/dev.c:6680)    \u003c/IRQ\u003e  A response can only acknowledge a request that was actually sent, so do not match asoc-\u003estrreset_chunk while chunk-\u003etransport is NULL. Guarding the lookup covers all three completion sites.",
  "id": "DEBIAN-CVE-2026-89477",
  "modified": "2026-09-14T08:47:32.330173321Z",
  "published": "2026-09-11T20:19:29.063Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-89477"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-89477"
  ]
}