CVE-2026-76198: CAI Content Credentials File Read Vulnerability

CVE-2026-76198 Overview

CVE-2026-76198 is an improper input validation vulnerability [CWE-20] in Adobe CAI Content Credentials. An attacker can exploit the flaw to perform arbitrary file system reads and access sensitive files outside the intended access scope. Exploitation requires user interaction: the victim must open a malicious file crafted by the attacker. The vulnerability is local in nature and does not require prior authentication. Successful exploitation results in confidentiality impact through disclosure of file contents that the application should not expose. Adobe published details in security bulletin APSB26-110.

Critical Impact
Attackers can read arbitrary files from the victim's file system after convincing the user to open a malicious Content Credentials file, exposing sensitive data.

Affected Products

Adobe CAI Content Credentials
See Adobe Security Update APSB26-110 for affected version ranges
Applications embedding vulnerable versions of the Content Authenticity SDK

Discovery Timeline

2026-08-25 - CVE-2026-76198 published to NVD
2026-08-26 - Last updated in NVD database

Technical Details for CVE-2026-76198

Vulnerability Analysis

The vulnerability resides in how CAI Content Credentials parses and validates input from Content Credentials files. When a user opens a malicious file, the application processes attacker-controlled input without adequate validation. This allows references to file system paths outside the intended scope to be resolved and read during processing. The attacker gains access to file contents based on the privileges of the user running the application. No network access is required, and no elevated privileges are needed to trigger the flaw. The impact is limited to confidentiality; integrity and availability of the host are not directly affected.

Root Cause

The root cause is improper input validation [CWE-20] in the Content Credentials processing pipeline. The parser accepts file references or embedded paths from an untrusted document and resolves them against the local file system without enforcing scope restrictions. Adobe's advisory APSB26-110 documents the affected components and provides remediation details.

Attack Vector

Exploitation is local and requires user interaction. An attacker crafts a malicious Content Credentials file that contains embedded references designed to trigger arbitrary reads. The attacker delivers the file through phishing, a compromised website, or a shared file location. When the victim opens the file with a vulnerable version of CAI Content Credentials, the application reads targeted files from disk. Attackers can enumerate configuration files, application secrets, browser data, or SSH keys stored under the user's context.

No verified proof-of-concept code is publicly available. Refer to the Adobe Security Update APSB26-110 for authoritative technical details.

Detection Methods for CVE-2026-76198

Indicators of Compromise

Unexpected Content Credentials files (.c2pa, .json, or media containers with embedded manifests) received via email or downloaded from untrusted sources
CAI Content Credentials processes reading sensitive files such as /etc/passwd, SSH private keys, browser credential stores, or user configuration directories
File access patterns from the Content Credentials process that deviate from its normal working directory scope

Detection Strategies

Monitor process telemetry for CAI Content Credentials or SDK-hosting applications performing unexpected file reads outside their installation and working directories
Alert on Content Credentials handlers reading well-known sensitive paths (credential stores, key material, shell history)
Correlate file-open events for suspicious Content Credentials documents with subsequent sensitive file reads by the same process

Monitoring Recommendations

Enable endpoint file-access auditing for user profile directories and secret stores
Log parent-child process relationships when Content Credentials files are opened from email clients or browsers
Track download sources for Content Credentials files and flag those originating from untrusted domains

How to Mitigate CVE-2026-76198

Immediate Actions Required

Apply the security update referenced in Adobe Security Update APSB26-110 as soon as it is available for your deployment
Inventory applications that embed the Content Authenticity SDK and prioritize updates for user-facing tools
Instruct users not to open Content Credentials files received from untrusted or unverified sources

Patch Information

Adobe has published remediation guidance in security bulletin APSB26-110. Update CAI Content Credentials and any application embedding the Content Authenticity SDK to the fixed version listed in the advisory. Consult the Adobe Security Update APSB26-110 for exact version numbers and download locations.

Workarounds

Restrict opening Content Credentials files to a sandboxed user account with minimal file system privileges until patches are applied
Block or quarantine Content Credentials attachments at the email gateway from external senders
Use application allow-listing to prevent execution of untrusted SDK-embedded tools on sensitive workstations

bash

# Example: restrict file access on Linux using a dedicated low-privilege user
sudo useradd -m -s /bin/bash caiviewer
sudo -u caiviewer /path/to/cai-content-credentials /path/to/received.c2pa