SSRF in Anchore Quill

CVE-2026-31959

Quill provides simple mac binary signing and notarization from any platform. Quill before version v0.7.1 contains a Server-Side Request Forgery (SSRF) vulnerability when attempting to fetch the Apple notarization submission logs. 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 retrieving submission logs, Quill fetches a URL provided in the API response without validating that the scheme is https or that the host does not point to a local or multicast IP address. An attacker who can tamper with the response can supply an arbitrary URL, causing the Quill client to issue HTTP or HTTPS requests to attacker-controlled or internal network destinations. This could lead to exfiltration of sensitive data such as cloud provider credentials or internal service responses. Both the Quill CLI and library are affected when used to retrieve notarization submission logs. This vulnerability is fixed in 0.7.1.

Vulnerability class: SSRF (Server-Side Request Forgery)

EPSS: 0.001 (0.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-31959?
CVE-2026-31959 is a medium-severity vulnerability in Anchore Quill, classified under Server-Side Request Forgery (SSRF). CVSS score: 5.3/10. Published 2026-03-11.
How severe is CVE-2026-31959?
Medium severity. CVSS v3 base score is 5.3 out of 10.