CVE-2026-31960 is a resource exhaustion vulnerability categorized under CWE-770 affecting Anchore's Quill tool versions prior to 0.7.1. Quill facilitates macOS binary signing and notarization by interacting with Apple's notarization service over HTTPS. The vulnerability arises because Quill reads the entire HTTP response body from the notarization API into memory without imposing any size limits or throttling mechanisms. If an attacker can manipulate the HTTP response content—by injecting an arbitrarily large payload—Quill will consume excessive memory, potentially leading to application crashes or denial of service. Under normal circumstances, exploitation is highly unlikely because Apple's notarization service uses HTTPS with proper TLS certificate validation, preventing man-in-the-middle attacks. However, environments that deploy TLS-intercepting proxies (common in corporate networks for monitoring), have compromised or untrusted certificate authorities, or suffer from other trust boundary violations are vulnerable. Both the Quill command-line interface and its library components are affected when performing notarization operations. The vulnerability impacts availability only, with no confidentiality or integrity compromise. The issue was addressed and fixed in Quill version 0.7.1 by implementing appropriate limits on HTTP response body reads to prevent unbounded memory allocation.

The primary impact of CVE-2026-31960 is denial of service due to resource exhaustion. Organizations relying on Quill for macOS binary signing and notarization may experience crashes or service interruptions during the notarization process if an attacker can manipulate the notarization API responses. This can delay software release cycles and disrupt automated build or deployment pipelines. Since the vulnerability requires the ability to intercept or modify HTTPS traffic, environments with TLS interception proxies or compromised trust stores are at higher risk. Although the vulnerability does not affect confidentiality or integrity, the availability impact can be significant for development teams and CI/CD environments that depend on Quill. Additionally, repeated exploitation attempts could lead to operational instability or increased support costs. The lack of known exploits in the wild reduces immediate risk, but the presence of this vulnerability in widely used developer tooling warrants prompt remediation to avoid potential future attacks.

1. Upgrade Quill to version 0.7.1 or later, where the vulnerability is fixed by enforcing limits on HTTP response body size during notarization. 2. Review and restrict the use of TLS-intercepting proxies within the network, especially for developer environments, to prevent man-in-the-middle attacks on notarization traffic. 3. Ensure that all certificate authorities trusted by the environment are legitimate and have not been compromised. 4. Implement network segmentation to isolate build and notarization systems from untrusted networks. 5. Monitor notarization processes for abnormal memory usage or crashes that could indicate exploitation attempts. 6. Use endpoint security solutions to detect and prevent unauthorized interception or modification of HTTPS traffic. 7. Educate developers and DevOps teams about the risks of TLS interception and encourage secure handling of notarization operations. 8. Consider additional runtime memory limits or container resource constraints on systems running Quill to mitigate impact of potential resource exhaustion.