Security Digest · Vulnerability record · Known exploited
CVE-2026-34621: Adobe Acrobat and Reader Prototype Pollution Vulnerability
Exploited in the wild (CISA KEV). 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.
CISA KEV · added 2026-04-13 CVSS 8.6 High EPSS 2.2% · p82
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Adobe Acrobat and Reader. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-04-13, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-04-27; treat that as the outer limit, not the target.
- EPSS 2.2%, percentile 82: FIRST’s model estimates a 2.2% chance of exploitation activity in the next 30 days, higher than 82% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.
What it is
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.
CISA’s summary
Adobe Acrobat and Reader contain a prototype pollution vulnerability that allows for arbitrary code execution.
Weakness type: CWE-1321.
Product: Adobe Acrobat and Reader · Assigned by: adobe · Published: 2026-04-11
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Adobe | Acrobat DC | <= 26.001.21367 |
| Adobe | Acrobat Reader DC | <= 26.001.21367 |
| Adobe | Acrobat 2024 | <= 24.001.30356 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| adobe | 3.1 | 8.6 High | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
- Attack vector: local access needed
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2026-04-13; federal due date 2026-04-27. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 2.18% probability of exploitation activity in the next 30 days; percentile 82.
Timeline
- — CVE record published by adobe
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- helpx.adobe.com helpx.adobe.com
Vulnerability records
- CVE.org record CVE-2026-34621 cve.org
- NVD entry CVE-2026-34621 nvd.nist.gov
Government
All exploited Adobe vulnerabilities · Today’s Security Digest