Answer in brief
CVE-2026-34621 records a High severity vulnerability in Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321). The current sources mark it as known exploited. The current feed maps Adobe/Acrobat Reader (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Adobe/Acrobat Reader (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Adobe/Acrobat Readergeneric | 0 | Not reported |
Published upstream
Apr 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Apr 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Apr 13, 2026
Evidence: source:kev:kev:kev:recordAcrobat 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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-34621 records a High severity vulnerability in Acrobat Reader | Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') (CWE-1321). The current sources mark it as known exploited. The current feed maps Adobe/Acrobat Reader (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Adobe/Acrobat Reader (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Adobe/Acrobat Readergeneric | 0 | Not reported |
Published upstream
Apr 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Apr 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Apr 13, 2026
Evidence: source:kev:kev:kev:recordAcrobat 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.
Quoted source text, attributed separately from HOL analysis.