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IndesignApplication · Adobe

CVE-2026-21277

HIGH · 7.8 CVSS v3.1 Published 2026-01-13
Fix available
A fix is available. Upgrade to 20.5.1 / 21.1 or later.
See remediation →
81/100
Remediation priority · High
No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
InDesign Desktop versions 21.0, 19.5.5 and earlier are affected by a Heap-based Buffer Overflow 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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Adobe InDesign Desktop versions 21.0, 19.5.5 and earlier contain a heap-based buffer overflow vulnerability in file parsing logic. Successful exploitation allows arbitrary code execution in the context of the current user, but requires the victim to open a specially crafted malicious InDesign file.

MitigationApply the vendor patch by updating InDesign to the fixed version. Users should avoid opening InDesign files from untrusted or unknown sources until the patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
IndesignApplication
Affected:< 20.5.1>= 21.0, < 21.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed InDesign version
    Open Adobe InDesign, go to Help > About InDesign (or Help > About Adobe InDesign on Mac). The version number is displayed in the dialog box.
    Affected if The version shown is 21.0.x, 20.x below 20.5.1, or any version 19.5.5 and earlier.
  2. Confirm InDesign Desktop is present
    Search for 'InDesign' in the Windows Start menu or macOS Applications folder, or check Program Files (Windows) or /Applications (macOS) for an InDesign installation folder.
    Affected if Adobe InDesign Desktop application is installed on the system.
  3. Identify the specific version number
    In the About dialog, note the full version string (for example: 21.0.1, 20.4, 19.5). Compare against the vulnerable ranges: versions 21.0.x and versions below 20.5.1.
    Affected if The installed version falls within < 20.5.1 or >= 21.0 and < 21.1.
  4. Check for recent file open activity
    Review recent InDesign .indd, .idml, or .icml files opened from external or untrusted sources. These file types trigger the parsing logic.
    Affected if The user has recently opened InDesign files from unknown or untrusted sources, especially if the file originated externally.

The system is affected if Adobe InDesign Desktop is installed and the installed version is 21.0.x, 20.x below 20.5.1, or 19.5.5 and earlier.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 20.5.1 / 21.1 or later
Fixed in 20.5.121.1
Interim mitigation

Apply the vendor patch by updating InDesign to the fixed version. Users should avoid opening InDesign files from untrusted or unknown sources until the patch is applied.

Recommended fix High confidence

InDesign 20.5.1 or later (for 20.x branch); InDesign 21.1 or later (for 21.x branch)

  1. 1. Close any running instances of Adobe InDesign
  2. 2. Open Adobe Creative Cloud desktop application or navigate to adobe.com/downloads
  3. 3. Locate Adobe InDesign in your installed applications
  4. 4. If using version 20.x (< 20.5.1): Update to version 20.5.1 or later
  5. 5. If using version 21.0: Update to version 21.1 or later
  6. 6. Wait for the update to download and install completely
  7. 7. Restart your computer to ensure the update is fully applied
  8. 8. Verify the installed version by opening InDesign and checking Help > About InDesign
Caveat Users should back up custom workspaces, scripts, and preferences before updating, as major version upgrades may occasionally reset settings

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Indesign Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-21277 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data