CVE-2026-31959

CVE-2026-31959 is a medium-severity vulnerability in Anchore Quill with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Description

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-31959?
CVE-2026-31959 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-31959 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-31959?
CVE-2026-31959 affects Anchore Quill. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-31959?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-31959 have an EU (EUVD) identifier?
Yes. CVE-2026-31959 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11325.
When was CVE-2026-31959 published?
CVE-2026-31959 was published on 2026-03-11 and last updated on 2026-06-17.

References

Affected products (1)

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