CVE-2026-31960 in quill
Summary
by MITRE • 03/11/2026
Quill provides simple mac binary signing and notarization from any platform. Quill before version v0.7.1 has unbounded reads of HTTP response bodies during the Apple notarization process. Exploitation requires the ability to modify API responses from Apple's notarization service, which is not possible under standard network conditions due to HTTPS with proper TLS certificate validation; however, environments with TLS-intercepting proxies (common in corporate networks), compromised certificate authorities, or other trust boundary violations are at risk. When processing HTTP responses during notarization, Quill reads the entire response body into memory without any size limit. An attacker who can control or modify the response content can return an arbitrarily large payload, causing the Quill client to run out of memory and crash. The impact is limited to availability; there is no effect on confidentiality or integrity. Both the Quill CLI and library are affected when used to perform notarization operations. This vulnerability is fixed in 0.7.1.
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Analysis
by VulDB Data Team • 03/14/2026
The vulnerability identified as CVE-2026-31960 affects Quill, a tool designed for macOS binary signing and notarization from any platform. This security flaw exists in Quill versions prior to v0.7.1 and specifically targets the Apple notarization process where the application reads HTTP response bodies without implementing any size restrictions. The technical implementation flaw stems from unbounded memory allocation during HTTP response processing, creating a potential denial of service condition when the tool encounters unexpectedly large response payloads. The vulnerability operates within the context of network security protocols where HTTPS with proper TLS certificate validation normally prevents unauthorized modification of API responses from Apple's notarization service. However, the risk surface expands significantly in environments where trust boundaries are compromised through TLS-intercepting proxies commonly found in corporate networks, or where certificate authorities have been compromised, creating opportunities for attackers to manipulate response content.
The operational impact of this vulnerability manifests as a memory exhaustion condition that causes the Quill client to crash and become unavailable for legitimate notarization operations. This represents a classic availability attack where an attacker can consume all available memory resources through controlled manipulation of HTTP response bodies, effectively rendering the notarization service unusable for legitimate users. The attack requires specific environmental conditions to be exploitable, namely the ability to modify API responses from Apple's notarization service, which normally cannot be achieved due to secure HTTPS connections with proper certificate validation. However, when network security policies allow for man-in-the-middle attacks through proxy interception or when certificate authorities are compromised, the vulnerability becomes actionable. Both the command-line interface and library components of Quill are affected, meaning that the vulnerability impacts all usage patterns and integration methods that rely on notarization functionality.
The security implications extend beyond simple service disruption to represent a broader class of memory safety vulnerabilities that align with CWE-129, which addresses insufficient input validation leading to buffer overflows or memory exhaustion conditions. This vulnerability demonstrates poor resource management practices in network application development where response size limits are not implemented during HTTP processing operations. The ATT&CK framework categorizes this type of vulnerability under privilege escalation and denial of service techniques, specifically targeting system availability through resource exhaustion attacks. The fix implemented in Quill version 0.7.1 addresses the root cause by introducing bounded read limits for HTTP response bodies during the notarization process, ensuring that memory allocation remains within predictable bounds regardless of response size. Organizations should prioritize updating to the patched version and implement network monitoring to detect potential exploitation attempts, particularly in environments where TLS interception is permitted or where certificate validation might be bypassed. The vulnerability serves as a reminder of the importance of implementing proper input validation and resource management in network applications to prevent memory exhaustion attacks that can compromise system availability.