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Fencer Intel
medium 4.7

CVE-2026-57957 json

Papermark 0.22.0 - CORS Misconfiguration in Viewer Upload Endpoint

published 4mo ago modified 3d ago also EUVD-2026-40142

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

Is CVE-2026-57957 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4mo ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N
CNA 3.1 4.7 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N
CNA 4.0 2.3 CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • papermark papermark

Classification

Weakness
  • CWE-942 Permissive Cross-domain Security Policy with Untrusted Domains

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.