CVE-2026-34621
Acrobat Reader versions 24.001.30356, 26.001.21367 and earlier are affected by an Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') vulnerability that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
ACTIVELY EXPLOITED IN THE WILD
This vulnerability is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
Adobe Acrobat and Reader Prototype Pollution Vulnerability
Adobe Acrobat and Reader
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
4/13/2026
https://helpx.adobe.com/security/products/acrobat/apsb26-43.html ; https://nvd.nist.gov/vuln/detail/CVE-2026-34621
Vulnerability Summary
CVSS v3 Score
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS Score (Exploitation Probability)
This vulnerability has a 9.81% probability of being exploited in the next 30 days, ranking higher than 93% of all scored CVEs.
CWE Classification
Related Vulnerabilities
Same Weakness Type(CWE-1321)
Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.0 through 1.4.16 contain a prototype pollution vulnerability in `mergeDeep` after merging results of two standard schema validations with the same key. Due to the ordering of merging, there must be an any type that is set as a standalone guard, to allow for the `__proto__ prop` to be merged. When combined with GHSA-8vch-m3f4-q8jf this allows for a full RCE by an attacker. This issue is fixed in version 1.4.17. To workaround, remove the `__proto__ key` from body.
A Prototype pollution vulnerability in Kibana leads to arbitrary code execution via crafted HTTP requests to machine learning and reporting endpoints.
Prototype Pollution in Kibana can lead to code injection via unrestricted file upload combined with path traversal.
DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMPurify was vulnerable to prototype pollution. This vulnerability is fixed in 2.4.2.
Prototype Pollution in alykoshin mini-deep-assign v0.0.8 allows an attacker to execute arbitrary code or cause a Denial of Service (DoS) and cause other impacts via the _assign() method at (/lib/index.js:91)
Similar SeverityHIGH
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