VulnerabilityPublished 15 Sep 2026

CVE-2026-58200: jhb-software payload-plugins · Improper Verification of Cryptographic Signature

Affects jhb-software payload-pluginsSource CVE Database V5

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Not known to be exploited · CVSS 7.1 High : upgrade to 0.4.0 soon.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

7.1High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.4.0

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade jhb-software payload-plugins to 0.4.0.

Affected software

Product	Affected	Fixed in
jhb-softwarepayload-plugins	Affected >=0.3.0 <0.4.0	Fixed in 0.4.0

AI-suggested

Upgrade to version 0.4.0 or later of the payload-plugins where this vulnerability is fixed. No other mitigation is indicated or required by the vendor advisory.

Description

Payload Plugins is a collection of plugins designed to enhance Payload CMS. From 0.3.0 until 0.4.0, @jhb.software/payload-cloudinary-plugin deployments with clientUploads enabled expose POST /api/cloudinary-generate-signature, whose handler in cloudinary/src/getGenerateSignature.ts passes attacker-controlled body.paramsToSign directly to cloudinary.utils.api_sign_request without a key allowlist, collection policy, timestamp freshness check, or configured-folder enforcement. Any authenticated Payload user can obtain a valid Cloudinary HMAC-SHA1 signature for unauthorized parameters such as overwrite, type, notification_url, invalidate, folder, and public_id. The signature can authorize asset replacement, upload visibility changes, callbacks to attacker-selected URLs, cache invalidation, and uploads outside the intended folder. The client-visible Cloudinary API key is expected by the upload design, but the unrestricted server-side signature supplies the authorization value needed to complete these operations. This vulnerability is fixed in 0.4.0.

Impact

The vulnerability allows authenticated users to bypass intended restrictions on Cloudinary asset management by generating valid signatures for unauthorized operations. This can lead to unauthorized modification or replacement of assets, changes in upload visibility, triggering of callbacks to attacker-controlled URLs, cache invalidation, and uploads outside designated folders. There is no confidentiality impact reported, but integrity is highly impacted and availability impact is low.

Summary

The vulnerability (CVE-2026-58200) affects the @jhb.software/payload-cloudinary-plugin when clientUploads is enabled. The POST /api/cloudinary-generate-signature endpoint passes attacker-controlled body.paramsToSign directly to cloudinary.utils.api_sign_request without enforcing a key allowlist, collection policy, timestamp freshness, or folder restrictions. This allows any authenticated Payload user to generate valid Cloudinary HMAC-SHA1 signatures for unauthorized parameters such as overwrite, type, notification_url, invalidate, folder, and public_id. Consequently, attackers can perform unauthorized asset replacement, change upload visibility, trigger callbacks to attacker-chosen URLs, invalidate caches, and upload files outside the intended folder. The vulnerability is resolved in version 0.4.0.

CWE-347Improper Verification of Cryptographic Signature (opens in a new tab)
Base weaknessOWASP Top 10 A04:2025: Cryptographic Failures (opens in a new tab)
The product does not verify, or incorrectly verifies, the cryptographic signature for data.
OWASP Cheat Sheets
XML Security (opens in a new tab)
REST Security (opens in a new tab)
JSON Web Token for Java (opens in a new tab)
REST Assessment (opens in a new tab)
Cross-Site Request Forgery Prevention (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.2 (opens in a new tab)
V3.5.3 (opens in a new tab)
V13.2.6 (opens in a new tab)
Attack patterns
Padding Oracle Crypto Attack (opens in a new tab)
Signature Spoofing by Improper Validation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 15 Sep 2026, 16:46 UTC

WeaknessesCWE-347

Technical details

References

Community reviews

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