CVE-2026-102268

validatedZero produced an exploit or a check.

GHSA-ffc3-869f-jxw9 ↗EUVD-2026-88535 ↗

check availableZero validated a working check for it.not proven exploitableZero has a detection check, but hasn't produced a full working exploit yet.
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).+3.7dkevAttacks confirmed in the real world.
pip:PyJWT <= 2.13.0
fixed in 2.14.0
CWE-347 Improper Verification of Cryptographic Signature
ETK-2026-1, permanent identifier
pkg:pypi/PyJWT
+23h36mTTV
17mAI analysisAnalysis: how long the AI spent reversing this signal.
Check if you are vulnerable
timeline
0 = trigger signal
trigger signal (cve.org) +0dcheck available+1.0dagent stoppedpublic poc+3.7d
0
+2d
+3d
+4d

description

PyJWT versions before 2.14.0 can accept forged HMAC-signed JWTs when an application mixes HMAC and asymmetric algorithms in its verification allow-list and passes certain noncanonical PEM public keys as raw key bytes. An attacker who knows the public verification key can impersonate token claims under that deployment configuration.

mitigation

Upgrade PyJWT to version 2.14.0 or later. Until upgraded, configure each verification path to allow only its intended algorithm family; do not mix HMAC and asymmetric algorithms.

fixed in 2.14.0

check
available
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.
0.20%9th percentile
agent run time
17m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-09-28 20:26Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
+3.7d
Δ to kevAttacks confirmed in the real world.
–

outcome

Mechanism verified: the exploit fired on the vulnerable build and stayed silent on the patched one, but the server it ran against was ours, so no check ships for it.

source signals

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

  1. 2026-09-28 20:26Z
  2. 2026-09-28 20:26Z
  3. 2026-10-03 05:48Z

this entry in the feed

GET /api/v1/feed/CVE-2026-102268

{
  "etk_id": "ETK-2026-1",
  "cve_id": "CVE-2026-102268",
  "display_id": "CVE-2026-102268",
  "ghsa_id": "GHSA-ffc3-869f-jxw9",
  "euvd_id": "EUVD-2026-88535",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Algorithm confusion in PyJWT PEM key validation",
  "summary": "PyJWT versions before 2.14.0 can accept forged HMAC-signed JWTs when an application mixes HMAC and asymmetric algorithms in its verification allow-list and passes certain noncanonical PEM public keys as raw key bytes. An attacker who knows the public verification key can impersonate token claims under that deployment configuration.",
  "mitigation": "Upgrade PyJWT to version 2.14.0 or later. Until upgraded, configure each verification path to allow only its intended algorithm family; do not mix HMAC and asymmetric algorithms.",
  "vendor": "pip",
  "product": "pip:PyJWT",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        "<= 2.13.0"
      ],
      "ecosystem": "pip",
      "fixed_versions": [
        "2.14.0"
      ],
      "package_name": "PyJWT",
      "purl": "pkg:pypi/PyJWT"
    }
  ],
  "cwes": [
    347
  ],
  "cvss_score": 9.1,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
  "epss_score": 0.002,
  "epss_percentile": 0.0955,
  "epss_asof": "2026-10-20",
  "automation": "contextual",
  "check": true,
  "check_confidence_basis": "mechanism_verified",
  "exploit": false,
  "pipeline_minutes": 17.25130025,
  "t0_at": "2026-09-28T20:26:13.674000+00:00",
  "signals": {
    "check": {
      "at": "2026-09-29T20:02:37.101339+00:00",
      "days": 0.9836044830902778,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:26:13.674000+00:00",
      "url": null
    },
    "public_poc": {
      "at": "2026-10-02T13:12:13+00:00",
      "days": 3.6986033101851854,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:26:13.674000+00:00",
      "url": "https://github.com/covepseng/cve-2026-102268-poc"
    },
    "trigger_signal": {
      "at": "2026-09-28T20:26:13.674000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-09-28T20:26:13.674000+00:00",
      "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-ffc3-869f-jxw9"
    }
  }
}

published 2026-09-29 19:45Z
last change 2026-10-21 09:43Z

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