CVE-2026-21281: Adobe InCopy · Heap-based Buffer Overflow
Affects Adobe InCopySource CVE Database V5
Not known to be exploited · CVSS 7.8 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 13% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AdobeInCopy | Affected
| Fixed in– |
AI-suggested
1. Immediately implement strict policies to restrict opening InCopy files from untrusted or unknown sources. 2. Disable file preview features in email clients and file explorers to prevent accidental triggering of the vulnerability. 3. Employ endpoint detection and response (EDR) solutions capable of monitoring and blocking suspicious memory manipulation behaviors indicative of heap overflows. 4. Educate users about the risks of opening unsolicited or unexpected files, emphasizing caution with InCopy documents. 5. Use application whitelisting to limit execution of unauthorized code. 6. Monitor network and endpoint logs for unusual activity that could indicate exploitation attempts. 7. Once Adobe releases official patches, prioritize their deployment across all affected systems. 8. Consider sandboxing or isolating InCopy usage environments to contain potential compromise. 9. Regularly back up critical data to enable recovery in case of successful exploitation. 10. Coordinate with Adobe support channels for updates and advisories.
Description
InCopy 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.