VulnTideExploited vulnerabilities, by vendor. Data as of 28 Oct 2026.
Known exploitedIn CISA's KEV catalog since 13 April 2026Ransomware use: unknown
Adobe Acrobat and Reader

CVE-2026-34621: Adobe Acrobat and Reader Prototype Pollution Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 13 Apr 2026, 2 days after the CVE record was published.

How likely is exploitation in the next 30 days?
7.2%

EPSS score, percentile 94.3 of all scored records

How severe?
8.6 High

CVSS v3.1 base score, given by the CNA

What should I do?

CISA deadline 27 Apr 2026. Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Advisories and patches (1)

Which versions are affected?

Affected

  • 26.001.21367 and earlier
  • 26.001.21367 and earlier
  • 24.001.30356 and earlier

Unaffected 26.001.21411; 26.001.21411; 24.001.30362 (Win), 24.001.30360 (Mac)

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

Required action, set by CISA

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 due date for this action: 27 April 2026.

Advisories and patches

Linked from CISA's catalog entry

Affected products and versions

As listed in the CVE record.

Adobe Acrobat DC
StatusVersions
Affected26.001.21367 and earlier
Unaffected26.001.21411

Versions not listed are: unaffected.

Adobe Acrobat Reader DC
StatusVersions
Affected26.001.21367 and earlier
Unaffected26.001.21411

Versions not listed are: unaffected.

Adobe Acrobat 2024
StatusVersions
Affected24.001.30356 and earlier
Unaffected24.001.30362 (Win), 24.001.30360 (Mac)

Versions not listed are: unaffected.

Versions the record lists as unaffected: 26.001.21411, 24.001.30362 (Win), 24.001.30360 (Mac).

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

Adobe Acrobat and Reader contain a prototype pollution vulnerability that allows for arbitrary code execution.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

  • CISA added CVE-2026-34621 to its Known Exploited Vulnerabilities (KEV) catalog on 13 Apr 2026.
  • CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
  • The due date CISA sets for the required action is 27 Apr 2026.
  • The CVE record was published on 11 Apr 2026, 2 days before it was added to KEV.
  • The CVE record carries a CVSS v3.1 base score of 8.6 (High), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 7.2% (percentile 94.3), as of 28 Oct 2026.
  • CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321)

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.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

DateEvent
11 Apr 2026CVE record published
13 Apr 2026Added to CISA KEV
27 Apr 2026CISA due date for the required action
27 Aug 2026CVE record last updated

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