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Fencer Intel
medium 5.4

CVE-2026-126771 json

OpsTree REMS through 1.0.0 Stored XSS via Attachment Upload and Preview

published 16h ago modified 15h ago also EUVD-2026-123676

cvss
5.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
—
no EPSS score yet
public exploits
0
none known

Summary

OpsTree REMS through 1.0.0 contains a stored cross-site scripting vulnerability that allows authenticated attackers to inject scripts by uploading attachments with spoofed text/html Content-Type. Attackers can upload HTML files named like test.html.pdf that render in the REMS origin via Preview, executing JavaScript in victims' browsers.

Is CVE-2026-126771 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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Exploits and checks

  • gist.github.com https://gist.github.com/neelkotnis/ddf75e2cb7192180e6c9618d27d1e99b referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CNA 4.0 5.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/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
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected products

  • OpsTree Solutions REMS

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

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.