CVE-2026-52539Network attack vector

Administrative access via default JWT signing secret

Published Jul 30, 2026 · Updated Jul 30, 2026

Authentication bypass in Outstatic CMS 2.1.9 and earlier allows remote attackers to gain administrative access using forged JWTs. The TOKEN_SECRET constant uses OST_TOKEN_SECRET when set but otherwise substitutes a signing key embedded in the public constants.ts source file. Deployments without OST_TOKEN_SECRET accept attacker-signed session tokens carrying arbitrary user data and full administrative permissions.

CVSS severity9.1
Critical
EPSS probability0.30%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Outstatic CMS 2.1.9 and earlier allows remote attackers to gain administrative access using forged JWTs. The TOKEN_SECRET constant uses OST_TOKEN_SECRET when set but otherwise substitutes a signing key embedded in the public constants.ts source file. Deployments without OST_TOKEN_SECRET accept attacker-signed session tokens carrying arbitrary user data and full administrative permissions.

The record

CVE
CVE-2026-52539
Published
Jul 30, 2026
Updated
Jul 30, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-798, T1552.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 30, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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