Apostrophe up to 4.32.0 Utility /api/v1/article/:id apos.util.set/apos.util.get prototype pollution

Summaryinfo

A vulnerability marked as critical has been reported in Apostrophe up to 4.32.0. The impacted element is the function apos.util.set/apos.util.get of the file /api/v1/article/:id of the component Utility Module. The manipulation leads to prototype pollution. This vulnerability is traded as CVE-2026-71553. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Apostrophe up to 4.32.0. It has been rated as critical. This issue affects the function apos.util.set/apos.util.get of the file /api/v1/article/:id of the component Utility Module. The manipulation with an unknown input leads to a prototype pollution vulnerability. Using CWE to declare the problem leads to CWE-1321. The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

ApostropheCMS is an open-source Node.js content management system. In 4.32.0 and earlier, PATCH /api/v1/article/:id accepts the inherited path toString.call and passes it through the utility module to apos.util.set() and apos.util.get(), allowing an authenticated editor to overwrite the shared Object.prototype.toString function's call property and cause a persistent process-wide denial of service until restart.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-71553 since 08/06/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/17/2026). MITRE ATT&CK project uses the attack technique T1059 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Apostrophe

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29
• 4.30
• 4.31
• 4.32.0

CPE 2.3info

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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