Content Credentials SDK CVE-2026-76189

The vulnerability requires that the attacker be able to supply a crafted C2PA manifest file to the local execution environment of the c2pa_tool or an application embedding the Content Credentials Rust SDK. No authentication is required (PR:N) and no user interaction is required (UI:N), meaning the trigger can occur in automated file-processing pipelines without operator involvement. Exploitation is limited to local access scenarios (AV:L) - the attacker must be able to place or deliver the crafted file to a path accessible to the processing application. There is no network-reachable attack surface inherent to the SDK itself; however, web applications or services that accept file uploads and internally invoke the SDK would extend the effective reach to remote attackers supplying input files. Confidentiality and integrity are not impacted; only availability is affected.

The CVSS 3.1 base score is 6.2 (Medium) with vector AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. The local attack vector (AV:L) limits exposure compared to a network-reachable vulnerability, but the combination of low complexity, no required privileges, and no user interaction means any process or automated pipeline ingesting a crafted file can be targeted without operator involvement. The impact is confined to availability (A:H) with no confidentiality or integrity loss. EPSS data was not provided, and the CVE is not in the CISA KEV catalog, indicating no confirmed active exploitation at time of analysis. Real-world risk is primarily relevant to pipelines and applications that automatically process untrusted C2PA-signed media - such as content verification workflows, media ingest services, or automated watermarking tools. For interactive use where a human controls which files are processed, practical exploitability is further constrained. The DoS-only impact and local vector reduce urgency compared to remote code execution flaws, but automated media pipelines warrant prompt patching.

An attacker crafts a C2PA manifest file containing a specially constructed integer field that underflows during parsing - for example, a length or offset field set to zero or one that, when decremented internally, wraps to a large unsigned value. When an automated content verification pipeline or a user running c2pa_tool processes this file, the SDK crashes, taking down the application or worker process and denying the availability of the content credential verification service. No public proof-of-concept code has been identified at time of analysis.