CVE-2026-34671: Adobe C2pa Integer Overflow DOS Vulnerability

CVE-2026-34671 Overview

CVE-2026-34671 is an integer overflow vulnerability [CWE-190] affecting Adobe's Content Authenticity Initiative (CAI) Content Credentials libraries. The flaw impacts c2pa versions 0.78.2 and earlier, and c2pa-web versions 0.7.0 and earlier. An attacker with local access can trigger an arithmetic wraparound that crashes the application, producing a denial-of-service condition. Exploitation requires no user interaction and no authentication. The issue is tracked under Adobe Security Advisory APSB26-53.

Critical Impact
Local attackers can crash applications that process Content Credentials, disrupting provenance verification workflows for media assets.

Affected Products

Adobe c2pa (Rust) versions 0.78.2 and earlier
Adobe c2pa-web (Node.js) versions 0.7.0 and earlier
Applications embedding the Content Authenticity SDK for C2PA manifest processing

Discovery Timeline

2026-05-12 - CVE-2026-34671 published to NVD
2026-05-15 - Last updated in NVD database

Technical Details for CVE-2026-34671

Vulnerability Analysis

The Coalition for Content Provenance and Authenticity (C2PA) libraries provide cryptographic provenance metadata for digital media. The c2pa Rust crate and the c2pa-web Node.js binding parse C2PA manifests embedded in image, video, and audio assets. CVE-2026-34671 stems from an integer overflow or wraparound during this parsing process.

When the library performs arithmetic on attacker-controlled length or offset fields, the calculation can exceed the maximum value of the integer type. The wrapped value causes the library to misallocate buffers or compute invalid indices. The resulting fault terminates the host application, yielding a denial-of-service outcome.

The vulnerability impacts availability only. Confidentiality and integrity are not affected, according to the published CVSS vector.

Root Cause

The root cause is missing bounds validation on integer arithmetic during C2PA manifest deserialization. Length fields read from untrusted asset metadata are used in size calculations without checked-arithmetic semantics. The wrapped result drives downstream allocation or iteration logic that subsequently faults.

Attack Vector

The attack vector is local. An attacker delivers a crafted media file containing a malformed C2PA manifest to a target system running the vulnerable library. When the application invokes c2pa or c2pa-web to validate or read the manifest, parsing triggers the overflow and crashes the process. No authentication or user interaction is required to trigger the fault once the file is processed.

The vulnerability manifests during manifest deserialization. See the Adobe Security Advisory APSB26-53 for technical details.

Detection Methods for CVE-2026-34671

Indicators of Compromise

Repeated unexpected termination of applications that invoke c2pa or c2pa-web parsing routines
Crash dumps referencing C2PA manifest processing functions or panic messages from the Rust runtime
Media files with malformed JUMBF boxes or oversized length fields in embedded C2PA assertions

Detection Strategies

Inventory all software dependencies to identify usage of adobe:c2pa and adobe:c2pa-web packages and their versions
Monitor application logs for abnormal exit codes or Rust panic traces originating from C2PA parsing modules
Apply static composition analysis to Node.js and Rust projects to flag vulnerable package versions in dependency trees

Monitoring Recommendations

Alert on repeated crashes of services that process user-supplied media containing Content Credentials
Track ingestion pipelines for media files that consistently fail manifest validation with parser errors
Correlate process termination events with file ingestion events for media validation workers

How to Mitigate CVE-2026-34671

Immediate Actions Required

Upgrade c2pa Rust crate to a version above 0.78.2 as published in the Adobe advisory
Upgrade c2pa-web Node.js package to a version above 0.7.0
Audit application dependency manifests (Cargo.toml, package.json) for vulnerable versions and rebuild affected services

Patch Information

Adobe published fixes in Security Advisory APSB26-53. Consult the Adobe Content Authenticity SDK advisory for the exact fixed versions and release notes. Update both direct and transitive dependencies that pull in the vulnerable crates or modules.

Workarounds

Restrict processing of untrusted media files in environments running the vulnerable library versions
Isolate C2PA parsing in sandboxed worker processes that can be restarted on crash without affecting the parent service
Validate file size and structural limits before passing assets to the C2PA library

bash

# Update vulnerable dependencies
# Rust project
cargo update -p c2pa

# Node.js project
npm install c2pa-web@latest
npm audit