# CVE-2026-34631: Adobe InCopy out-of-bounds write

Source: https://junglewise.ai/threats/cve-2026-34631-adobe-incopy-out-of-bounds-write  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-14. Updated: 2026-07-25  
License: CC BY 4.0 with a link back

CVE-2026-34631 · Severity: high · CVSS 7.8 · Published 2026-04-14

Adobe InCopy, a professional writing and editing software, is affected by a security flaw that could allow an attacker to take control of a user's computer. To exploit this, an attacker must trick a user into opening a specially crafted malicious file. If successful, the attacker could run unauthorized commands or access sensitive data with the same permissions as the logged-in user.

Technologies: [Adobe InCopy](https://junglewise.ai/threats/technologies/incopy). Vendors: [Adobe](https://junglewise.ai/threats/vendors/adobe).

## Quick answers

**Is CVE-2026-34631 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-34631 being exploited in the wild.

**How severe is CVE-2026-34631?** High severity, with a CVSS score of 7.8, published 14 April 2026.

**Which products and versions are affected?** Adobe InCopy 20.5.2, 21.2 and earlier.

**Is there a fix for CVE-2026-34631?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-34631 attacked?** It is attacked with local access, in a network appliance.

**Am I affected by CVE-2026-34631?** Check whether you run Adobe InCopy at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

An out-of-bounds write vulnerability (CWE-787) exists in Adobe InCopy versions 20.5.2, 21.2 and earlier. The flaw occurs when the application writes data past the end of an intended buffer, which can be triggered by processing a specially crafted file. An attacker can leverage this to achieve arbitrary code execution in the context of the current user. Exploitation requires local access to deliver the file and relies on user interaction (opening the malicious document). Adobe has addressed this in advisory APSB26-33.

## Affected products

- Adobe InCopy 20.5.2, 21.2 and earlier

## Timeline

- 2026-04-14: disclosed
- 2026-04-14: advisory

## References

- [https://helpx.adobe.com/security/products/incopy/apsb26-33.html](https://helpx.adobe.com/security/products/incopy/apsb26-33.html)

## Related threats

- [Adobe InCopy stack-based buffer overflow](https://junglewise.ai/threats/cve-2026-34708-adobe-incopy-stack-based-buffer-overflow)
- [Adobe InCopy heap overflow in file parsing](https://junglewise.ai/threats/cve-2026-34707-adobe-incopy-heap-overflow-in-file-parsing)
- [Adobe InCopy out-of-bounds write vulnerability](https://junglewise.ai/threats/cve-2026-34706-adobe-incopy-out-of-bounds-write-vulnerability)
- [Adobe InCopy out-of-bounds read in file parsing](https://junglewise.ai/threats/cve-2026-27287-adobe-incopy-out-of-bounds-read-in-file-parsing)
- [InCopy versions 20.5, 19.5.5 and earlier are affected by a Use After Free vulnerability that could result in arbitrary…](https://junglewise.ai/threats/cve-2025-61818-incopy-versions-20-5-19-5-5-and-earlier-are-affected-by-a-use)