CVE-2026-97031

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

GHSA-hq7w-2xrq-wp2j ↗EUVD-2026-95422 ↗

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.
Go standard library crypto/tls < 1.26.9; >= 1.27.0-0, < 1.27.2
fixed in 1.26.9, 1.27.2
ETK-2026-1997Zero's internal tracking ID, independent of the CVE number., permanent identifier
1d 09h 51msince last run
16mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = cve.org publication
trigger signal (cve.org) +0hwaiting for further signals+267h56m
0
+2h
+4h
+6h
+8h
+10h

description

Go crypto/tls servers that process ECH ClientHello messages are affected by malformed inputs with multiple outer-extension references. A remote client able to reach such a server can cause excessive memory consumption and potentially disrupt the process.

mitigation

Upgrade Go crypto/tls to Go 1.26.9 or 1.27.2. Until upgraded, limit untrusted network access to TLS services that process ECH traffic.

fixed in 1.26.9, 1.27.2

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.
no
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
0.39%32nd percentile
agent run time
16m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-08 22:53Z
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. 2026-10-08 22:53Z
    ghsa: trigger signal, started the run
  2. 2026-10-08 22:53Z

this entry in the feed

GET /api/v1/feed/CVE-2026-97031

{
  "etk_id": "ETK-2026-1997",
  "cve_id": "CVE-2026-97031",
  "display_id": "CVE-2026-97031",
  "ghsa_id": "GHSA-hq7w-2xrq-wp2j",
  "euvd_id": "EUVD-2026-95422",
  "status": "published",
  "anchor_state": "anchored",
  "title": "ECH parsing memory exhaustion in Go crypto/tls",
  "summary": "Go crypto/tls servers that process ECH ClientHello messages are affected by malformed inputs with multiple outer-extension references. A remote client able to reach such a server can cause excessive memory consumption and potentially disrupt the process.",
  "mitigation": "Upgrade Go crypto/tls to Go 1.26.9 or 1.27.2. Until upgraded, limit untrusted network access to TLS services that process ECH traffic.",
  "vendor": "Go standard library",
  "product": "crypto/tls",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, < 1.26.9",
        ">= 1.27.0-0, < 1.27.2"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "1.26.9",
        "1.27.2"
      ],
      "package_name": "crypto/tls",
      "purl": null
    }
  ],
  "cwes": null,
  "cvss_score": 7.5,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss_score": 0.0039,
  "epss_percentile": 0.3217,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 15.582149933333334,
  "t0_at": "2026-10-08T22:53:58.775000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-08T22:53:58.775000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-08T22:53:58.775000+00:00",
      "url": "https://github.com/advisories/GHSA-hq7w-2xrq-wp2j"
    }
  }
}

published 2026-10-18 18:10Z
last change 2026-10-21 12:26Z

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