What’s Vulnerable › Vulnerabilities

CVE-2026-57957: Papermark 0.22.0 - CORS Misconfiguration in Viewer Upload Endpoint

• Severity: medium (CVSS 4.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-29 · updated 2026-07-14
• Weakness: CWE-942

Description

Papermark through 0.22.0 contains a cross-origin resource sharing (CORS) misconfiguration vulnerability that allows unauthenticated remote attackers to perform credentialed cross-origin requests by exploiting the TUS-based viewer upload endpoint reflecting arbitrary request Origins with Access-Control-Allow-Credentials set to true. Attackers can lure authenticated victims to malicious pages that silently issue credentialed cross-origin requests to upload arbitrary files into victim datarooms and read credentialed responses.

Affected products

• papermark: through 0.22.0

References

• https://github.com/AstoKr/papermark/pull/1
• https://github.com/papermark/papermark/issues/2178
• https://www.vulncheck.com/advisories/papermark-cors-misconfiguration-in-viewer-upload-endpoint

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