How to Fix CVE-2026-34690: Stack Buffer Overflow in After Effects
Related fixes
Other vulnerabilities in the same area that are worth patching alongside this one:
- How to Fix CVE-2026-21335: Command Injection in Substance3D - Designer — Command Injection in Substance3D - Designer
- How to Fix CVE-2026-27285: Heap buffer overflow in InDesign Desktop — Heap buffer overflow in InDesign Desktop
- How to Fix CVE-2026-34618: Out-of-bounds write in Illustrator , Out-of-bounds write in Illustrator
- How to Fix CVE-2026-27298: Access of resource using incompatible type in Adobe Framemaker , Access of resource using incompatible type in Adobe Framemaker
- How to Fix CVE-2026-34637: Command Injection in Premiere Pro , Command Injection in Premiere Pro
*By Sai Kiran Pandrala*
| Severity | CVSS 7.8 - High |
|---|---|
| Actively exploited? | Not currently listed in CISA KEV |
| Affected | 0 <= 25.6.4 |
| Fixed in | See vendor advisory |
| Type (CWE) | CWE-121: Stack-based Buffer Overflow () |
What is CVE-2026-34690?
CVE-2026-34690 is a stack-based buffer overflow in After Effects. A remote attacker can send a crafted message that overflows a fixed-size stack buffer, corrupting the return address and, on un-mitigated builds, achieving code execution. Vendor description: After Effects versions 26.0, 25.6.4 and earlier are affected by a Stack-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.
Why this CVE matters
Stack-based buffer overflows in network-reachable services have driven some of the highest-impact incidents of the past two years. Modern compiler protections raise the bar, but real-world exploits for unpatched appliances continue to appear quickly after disclosure.
For deployments of After Effects that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.
Am I affected?
You are affected if your installation matches any of these version ranges:
- After Effects: 0 <= 25.6.4
Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.
Check the product's About dialog for the installed version, or inspect the install directory for the version file documented in the vendor's release notes.
How to fix CVE-2026-34690
- Read the vendor advisory in full: https://helpx.adobe.com/security/products/after_effects/apsb26-48.html
- Upgrade After Effects to the patched build listed in the vendor advisory.
- Back up the configuration (and database, where applicable) before upgrading.
- Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
- Restart the affected service so the patched binary loads, then verify the new version (see verification section).
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Patch via your OS package manager
Vendor advisory (always check this first for exact fixed version and any
prerequisites): https://helpx.adobe.com/security/products/after_effects/apsb26-48.html
# Vendor advisory: https://helpx.adobe.com/security/products/after_effects/apsb26-48.html
# Debian / Ubuntu: pull the patched build of after-effects from your distro repository.
sudo apt update
sudo apt install --only-upgrade after-effects
# RHEL / Rocky / AlmaLinux / Fedora
sudo dnf upgrade after-effects
# openSUSE
sudo zypper update after-effects
# Verify the running version matches the fixed-in version (<patched-version>).
after-effects --version || dpkg -s after-effects | grep -i version || rpm -q after-effects
# Windows: pull the latest cumulative updates that include this CVE's fix.
Install-Module PSWindowsUpdate -Force -SkipPublisherCheck
Import-Module PSWindowsUpdate
Get-WindowsUpdate -AcceptAll -Install -AutoReboot
# If a specific KB is referenced in the advisory, install it directly.
# Get-WindowsUpdate -KBArticleID KBxxxxxxx -AcceptAll -Install -AutoReboot
Verify the fix landed
# Vendor advisory: https://helpx.adobe.com/security/products/after_effects/apsb26-48.html
# 1. Confirm the running version matches the fixed-in version listed above.
# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
# The scanner should no longer flag this CVE on the patched target.
# 3. Inspect recent service / kernel logs for crash-loops or rollback events.
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"
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If you cannot patch immediately
Block network reachability to the vulnerable service from untrusted networks and apply the patched build. Memory-corruption bugs cannot be reliably mitigated at the network layer; the patch is the fix.
How to verify the fix worked
- After applying the patch, verify the running version in the product's admin UI or via the vendor-documented CLI command.
- Confirm the patched build matches the version listed in the vendor advisory.
- Run an authenticated vulnerability scan with a current signature set and confirm the scanner no longer flags CVE-2026-34690.
- Review logs for the entire pre-patch window for indicators of compromise listed in the vendor or CISA advisory.
- Confirm any network-layer mitigations that were applied as a stopgap have been reverted (or left in place intentionally) once the patch is verified.
If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for repeated service restarts, crash logs from the affected daemon, and core files generated around the time of any anomalous traffic. A memory-corruption flaw used for exploitation often leaves a trail of failed attempts before the successful one.
Frequently asked questions
Is CVE-2026-34690 being exploited in the wild?
Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.
Will a WAF or IDS rule fully mitigate CVE-2026-34690?
No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.
How long should I plan for the upgrade?
Typical vendor-documented upgrade windows for After Effects run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.
References
- Official vendor advisory: https://helpx.adobe.com/security/products/after_effects/apsb26-48.html
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-34690
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*