CVE-2026-116264

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

GHSA-8mr9-wfcj-h3rm ↗EUVD-2026-112293 ↗

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.
MIME-tools < 5.521
fixed in 5.521
CWE-436 Interpretation Conflict
ETK-2026-2892Zero's internal tracking ID, independent of the CVE number., permanent identifier
1d 04h 39msince last run
21mAI analysisAnalysis: how long the AI spent reversing this signal.
timeline
0 = trigger signal
trigger signal (cve.org) +0hwaiting for further signals+0h53m
0
+2h
+4h
+6h
+8h
+10h
+12h

description

MIME-tools versions before 5.521 can stop processing multipart Content-Type parameters after an invalid parameter. A remote sender may cause an attachment to be missed by filters that rely on ambiguity detection while a recipient mail client still displays it; this requires processing a crafted multipart message.

mitigation

Upgrade MIME-tools to version 5.521 or later. Until upgraded, ensure mail filtering does not rely solely on MIME-tools ambiguity detection for attachment inspection.

fixed in 5.521

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.
–
agent run time
21m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-28 17:31Z
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, not validated: no deterministic check could cover this one, and no technique passed our review.

source signals

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

  1. 2026-10-28 17:31Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-116264

{
  "etk_id": "ETK-2026-2892",
  "cve_id": "CVE-2026-116264",
  "display_id": "CVE-2026-116264",
  "ghsa_id": "GHSA-8mr9-wfcj-h3rm",
  "euvd_id": "EUVD-2026-112293",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Multipart parameter parsing inconsistency in MIME-tools",
  "summary": "MIME-tools versions before 5.521 can stop processing multipart Content-Type parameters after an invalid parameter. A remote sender may cause an attachment to be missed by filters that rely on ambiguity detection while a recipient mail client still displays it; this requires processing a crafted multipart message.",
  "mitigation": "Upgrade MIME-tools to version 5.521 or later. Until upgraded, ensure mail filtering does not rely solely on MIME-tools ambiguity detection for attachment inspection.",
  "vendor": null,
  "product": "MIME-tools",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 0, < 5.521"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "5.521"
      ],
      "package_name": "MIME-tools",
      "purl": null
    }
  ],
  "cwes": [
    436
  ],
  "cvss_score": null,
  "cvss_src": null,
  "cvss_vector": null,
  "epss_score": null,
  "epss_percentile": null,
  "epss_asof": null,
  "automation": "contextual",
  "check": false,
  "check_confidence_basis": null,
  "exploit": false,
  "pipeline_minutes": 20.918873483333332,
  "t0_at": "2026-10-28T17:31:52.187000+00:00",
  "signals": {
    "trigger_signal": {
      "at": "2026-10-28T17:31:52.187000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-28T17:31:52.187000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-116264"
    }
  }
}

published 2026-10-28 18:04Z
last change 2026-10-29 17:31Z

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