CVE-2026-8739Public exploitNetwork attack vector

Unauthenticated private-file access via hard-coded signing key

Published May 17, 2026 · Updated May 17, 2026

Hard-coded key use in PublicCMS 5.202506.d allows remote attackers to download private files without authentication. SafeConfigComponent.getSignKey uses the privatefile_key value as a fixed signing secret, enabling forged private-file URLs. The exposed web path is remotely reachable, and the reported consequence is limited to unauthorized private-file access.

CVSS severity5.3
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hard-coded key use in PublicCMS 5.202506.d allows remote attackers to download private files without authentication. SafeConfigComponent.getSignKey uses the privatefile_key value as a fixed signing secret, enabling forged private-file URLs. The exposed web path is remotely reachable, and the reported consequence is limited to unauthorized private-file access.

The record

CVE
CVE-2026-8739
Published
May 17, 2026
Updated
May 17, 2026
Vendor
Tianjin Black Core Technology Co., LTD.
Product
PublicCMS
Classifications
CWE-321, CWE-320
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2026CVE publishedPublication date reported by the CVE source.
  2. May 17, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.202506.d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tianjin Black Core Technology Co., LTD. · PublicCMSversion=5.202506.d

Published CVSS scores

5.3VulDB CNACVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R
5.0VulDB CNAAV:N/AC:L/Au:N/C:N/I:P/A:N
5.3VulDB CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
6.9VulDB CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-321Use of Hard-coded Cryptographic Key
CWE-320Key Management Error

Public exploit references

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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