Answer in brief
CVE-2021-28550 records a High severity vulnerability in Adobe Acrobat Reader use after free vulnerability could lead to arbitrary code execution. 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 | unspecified || unspecified || unspecified || unspecified | Not reported |
Published upstream
Sep 2, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:recordAcrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a Use After Free vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve 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-2021-28550 records a High severity vulnerability in Adobe Acrobat Reader use after free vulnerability could lead to arbitrary code execution. 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 | unspecified || unspecified || unspecified || unspecified | Not reported |
Published upstream
Sep 2, 2021
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:recordAcrobat Reader DC versions versions 2021.001.20150 (and earlier), 2020.001.30020 (and earlier) and 2017.011.30194 (and earlier) are affected by a Use After Free vulnerability. An unauthenticated attacker could leverage this vulnerability to achieve 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.