CVE-2026-57957

EUVD-2026-40142

29.06.2026, 18:16

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.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
VulnCheck	CNA	4.7 MEDIUM	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Base Score

CVSS 3.x

EPSS Score

Percentile: Unknown

Early Detection

Affected products identified ahead of NVD analysis through intelligence sources.

Vendor	Product	Version	Source
papermark	papermark	𝑥 ≤ 0.22.0	CNA

Common Weakness Enumeration

CWE-942 - Permissive Cross-domain Policy with Untrusted Domains
The software uses a cross-domain policy file that includes domains that should not be trusted.

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