CVE-2026-21276

Memory Safety in Adobe Indesign ≤ 20.5.1

Memory Safety

Published

13 January 2026

Modified

14 January 2026

Patch / advisory

View advisory

CVSS Score v3.1 7.8

Click a component to see what it means

Raw vector

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

EPSS Score 0.0022 13th percentile

Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-21276 is a high-severity Access of Uninitialized Pointer (CWE-824) vulnerability in Adobe Indesign. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 13th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-21276 is an Access of Uninitialized Pointer vulnerability (CWE-824) affecting Adobe InDesign Desktop versions 21.0, 19.5.5, and earlier. This flaw allows arbitrary code execution in the context of the current user when a victim opens a malicious file, as disclosed in the CVE published on 2026-01-13. The vulnerability has a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H), indicating high confidentiality, integrity, and availability impacts with low attack complexity but requiring local access and user interaction.

Exploitation requires an attacker to trick a user into opening a specially crafted malicious file using the affected InDesign versions. No privileges are needed (PR:N), making it accessible to any local attacker, though delivery typically involves social engineering such as phishing emails with malicious InDesign documents (.indd files). Successful exploitation results in arbitrary code execution with the privileges of the current user, potentially enabling full system compromise if the user has elevated rights.

Adobe's security bulletin APSB26-02 at https://helpx.adobe.com/security/products/indesign/apsb26-02.html details patches and mitigation steps for resolving this vulnerability in supported InDesign versions. Security practitioners should advise users to apply these updates promptly and avoid opening untrusted files in vulnerable installations.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-2070

Vulnerability Data

InDesign Desktop versions 21.0, 19.5.5 and earlier are affected by an Access of Uninitialized Pointer 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.

CWE(s): CWE-824

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation

Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.

attack.mitre.org →

T1190 Exploit Public-Facing Application Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

attack.mitre.org →

T1203 Exploitation for Client Execution Execution

Adversaries may exploit software vulnerabilities in client applications to execute code.

attack.mitre.org →

T1210 Exploitation of Remote Services Lateral Movement

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

attack.mitre.org →

T1211 Exploitation for Stealth Stealth

Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.

attack.mitre.org →

T1212 Exploitation for Credential Access Credential Access

Adversaries may exploit software vulnerabilities in an attempt to collect credentials.

attack.mitre.org →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-21275Same product: Adobe Indesign

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CVE-2023-26334Same product: Apple Macos

CVE-2023-47054Same product: Apple Macos

CVE-2024-20785Same product: Adobe Indesign

CVE-2024-41852Same product: Adobe Indesign

CVE-2023-26387Same product: Apple Macos

CVE-2024-49544Same product: Adobe Indesign

CVE-2024-20783Same product: Adobe Indesign

Affected Assets

adobe

indesign

≤ 20.5.1 · 21.0 — 21.1

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover uninitialized pointer accesses through static analysis, dynamic testing, or fuzzing before deployment.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development processes and tools enables use of analyzers or coding standards that identify uninitialized pointer defects.

SA-8 Security and Privacy Engineering Principles partial match

Security engineering principles can mandate memory-safety practices and language choices that structurally avoid uninitialized pointer use.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match

prevents

Secure SDLC practices directly prevent uninitialized pointer bugs via coding standards, analysis, and reviews, but eliminating this single weakness only partially fulfills the broader control.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.29 Security testing in development and acceptance mostly match

finds

Security testing can detect uninitialized pointer usage before release.

A.8.25 Secure development life cycle partial match

prevents

Secure development life cycle mandates practices that reduce uninitialized pointer defects.

A.8.26 Application security requirements partial match

degrades

Application security requirements can specify pointer initialization rules.

A.8.27 Secure system architecture and engineering principles partial match

degrades

Secure architecture principles discourage unsafe pointer handling.