CVE-2026-98374

waiting for further signalsZero needs more public information before it can validate it.

GHSA-2q84-vc4j-mp23 ↗EUVD-2026-94323 ↗

no check availablenot proven exploitable
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).kevAttacks confirmed in the real world.
Linux 5.11
fixed in fad6d429651e748365e93ca54645accc212f0018, c5b4da1f403a658c1c19766be2b426003ada419f, 71d45049b0d631dfdbf3c65305f7fca676de023b, e3ea71cb1408a013ed4e8a757b815f1a919324bd, 631aa4cb45099f09e9385dd786bd291c6270bfc4, 0f87720c7e4bcab07c24888b3cf12bfe857bb90e, fe99bbeee5c5dbd3abc30721a8079ced59649d97
ETK-2026-949, permanent identifier
13d 13h 46msince last run
31mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = cve.org publication
trigger signal (cve.org) +0hwaiting for further signals+19h01m
0
+2h
+4h
+6h
+8h
+10h

description

Linux kernels with the affected TCP retransmission handling can retain a reference to a freed packet buffer during SYN-ACK processing. An unprivileged client using TCP Fast Open may trigger a kernel use-after-free when the required ICMP and simultaneous-open network conditions occur.

mitigation

Update to a Linux kernel release containing the applicable fix commit: fad6d429651e748365e93ca54645accc212f0018, c5b4da1f403a658c1c19766be2b426003ada419f, 71d45049b0d631dfdbf3c65305f7fca676de023b, e3ea71cb1408a013ed4e8a757b815f1a919324bd, 631aa4cb45099f09e9385dd786bd291c6270bfc4, 0f87720c7e4bcab07c24888b3cf12bfe857bb90e, or fe99bbeee5c5dbd3abc30721a8079ced59649d97. Until updated, reduce exposure by disabling or restricting TCP Fast Open where operationally feasible.

fixed in fad6d429651e748365e93ca54645accc212f0018, c5b4da1f403a658c1c19766be2b426003ada419f, 71d45049b0d631dfdbf3c65305f7fca676de023b, e3ea71cb1408a013ed4e8a757b815f1a919324bd, 631aa4cb45099f09e9385dd786bd291c6270bfc4, 0f87720c7e4bcab07c24888b3cf12bfe857bb90e, fe99bbeee5c5dbd3abc30721a8079ced59649d97

check
no
exploit
no
automationDeterministic: a check that runs on its own, the same request on every target. Contextual: an agentic technique that needs to be applied per target, for bugs that depend on contextual flows.
contextual
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
–
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
0.16%4th percentile
agent run time
31m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-07 13:01Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
–
Δ to kevAttacks confirmed in the real world.
–

outcome

Contextual: an exploit technique exists, but no deterministic check could cover this one.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

  1. 2026-10-07 13:01Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-98374

{
  "etk_id": "ETK-2026-949",
  "cve_id": "CVE-2026-98374",
  "display_id": "CVE-2026-98374",
  "ghsa_id": "GHSA-2q84-vc4j-mp23",
  "euvd_id": "EUVD-2026-94323",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Use-after-free in Linux TCP SYN-ACK retransmission",
  "summary": "Linux kernels with the affected TCP retransmission handling can retain a reference to a freed packet buffer during SYN-ACK processing. An unprivileged client using TCP Fast Open may trigger a kernel use-after-free when the required ICMP and simultaneous-open network conditions occur.",
  "mitigation": "Update to a Linux kernel release containing the applicable fix commit: fad6d429651e748365e93ca54645accc212f0018, c5b4da1f403a658c1c19766be2b426003ada419f, 71d45049b0d631dfdbf3c65305f7fca676de023b, e3ea71cb1408a013ed4e8a757b815f1a919324bd, 631aa4cb45099f09e9385dd786bd291c6270bfc4, 0f87720c7e4bcab07c24888b3cf12bfe857bb90e, or fe99bbeee5c5dbd3abc30721a8079ced59649d97. Until updated, reduce exposure by disabling or restricting TCP Fast Open where operationally feasible.",
  "vendor": "Linux",
  "product": "Linux",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < fad6d429651e748365e93ca54645accc212f0018",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < c5b4da1f403a658c1c19766be2b426003ada419f",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < 71d45049b0d631dfdbf3c65305f7fca676de023b",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < e3ea71cb1408a013ed4e8a757b815f1a919324bd",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < 631aa4cb45099f09e9385dd786bd291c6270bfc4",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < 0f87720c7e4bcab07c24888b3cf12bfe857bb90e",
        ">= c31b70c9968fe9c4194d1b5d06d07596a3b680de, < fe99bbeee5c5dbd3abc30721a8079ced59649d97"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "fad6d429651e748365e93ca54645accc212f0018",
        "c5b4da1f403a658c1c19766be2b426003ada419f",
        "71d45049b0d631dfdbf3c65305f7fca676de023b",
        "e3ea71cb1408a013ed4e8a757b815f1a919324bd",
        "631aa4cb45099f09e9385dd786bd291c6270bfc4",
        "0f87720c7e4bcab07c24888b3cf12bfe857bb90e",
        "fe99bbeee5c5dbd3abc30721a8079ced59649d97"
      ],
      "package_name": "Linux",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        "5.11"
      ],
      "ecosystem": null,
      "fixed_versions": [],
      "package_name": "Linux",
      "purl": null
    }
  ],
  "cwes": null,
  "cvss_score": null,
  "cvss_src": null,
  "cvss_vector": null,
  "epss_score": 0.0016,
  "epss_percentile": 0.0492,
  "epss_asof": "2026-10-21",
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 31.49141283333333,
  "t0_at": "2026-10-07T13:01:48.600000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-07T13:01:48.600000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-07T13:01:48.600000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-98374"
    }
  }
}

published 2026-10-08 07:31Z
last change 2026-10-21 20:26Z

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