CVE-2026-54594 in Monorepo
Summary
by MITRE • 09/17/2026
OmniBlocks is a monorepo for the OmniBlocks project. Prior to the June 6, 2026 workflow remediation, .github/workflows/disc.yml runs for the issues opened event and the issues edited event and invokes the createDiscussion mutation whenever an issue is classified as off-topic, without recording that the issue was already converted or otherwise suppressing duplicate runs. A user who creates one off-topic issue and repeatedly edits its description before conversion completes can therefore cause multiple discussions to be created for the same issue, producing discussion spam and additional moderation work. This issue is fixed with commit 627e0f0a16a7d74b09128106b57dd7e85d2545df.
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Analysis
by VulDB Data Team • 09/17/2026
The vulnerability described involves a logic flaw within the GitHub Actions workflow configuration for the OmniBlocks project, specifically in the disc.yml file prior to its remediation on June 6, 2026. This workflow is designed to automate community moderation by monitoring issues and converting off-topic discussions into dedicated discussion threads via the createDiscussion mutation. The core technical deficiency lies in the lack of idempotency checks or state tracking within the automation logic. When an issue is flagged as off-topic, the system triggers a conversion process without verifying whether that specific issue has already been processed or converted by a previous run of the same workflow. This absence of duplicate detection mechanisms creates a race condition and logical error where multiple instances of the mutation can be executed for a single source event.
The operational impact is most severe when an end-user modifies the description of an off-topic issue repeatedly before the initial conversion process completes or finalizes. Each edit triggers the issues_edited event, which in turn re-invokes the workflow logic. Because the system does not record that the issue was already queued for conversion or actively being processed, it proceeds to create a new discussion thread for each subsequent edit. This results in significant discussion spam within the project repository, cluttering the interface with redundant threads and degrading the user experience for both developers and community members. Furthermore, this behavior imposes unnecessary moderation overhead, as maintainers must manually identify and merge or delete these duplicate discussions rather than dealing with a single consolidated thread.
From a security and reliability perspective, this flaw aligns with CWE-841 Improper Enforcement of Behavioral Workflow, where the system fails to enforce proper sequencing or state management in automated processes. It also reflects aspects of CWE-672 Operation on Uninitialized Variable if one considers the lack of tracking variables for processed issues as a form of uninitialized state handling within the workflow context. In terms of MITRE ATT&CK, this can be categorized under T1498 Network Denial of Service via Resource Exhaustion, although in this specific case, it is more accurately described as an unintentional denial of service through resource exhaustion caused by application logic errors rather than malicious exploitation. The vulnerability does not involve external attackers but stems from internal workflow design flaws that are triggered by normal user interactions.
The remediation for this issue was implemented via commit 627e0f0a16a7d74b09128106b57dd7e85d2545df, which likely introduced mechanisms to track the state of issues being processed. Effective mitigations in such scenarios typically involve implementing a database or cache entry that records the issue ID once it has been flagged for conversion, ensuring subsequent edits do not trigger duplicate mutations. Additionally, introducing idempotency keys for the createDiscussion mutation can prevent multiple threads from being created even if the workflow runs multiple times concurrently. To further enhance robustness, developers should implement retry logic with exponential backoff and ensure that workflows check for existing discussion links on an issue before attempting to create a new one. Regular auditing of automation logs for duplicate actions is also recommended to detect similar logical flaws in other parts of the CI/CD pipeline or community management tools.