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Fencer Intel
medium 5.1

CVE-2026-52886 json

Notepad++: session.xml backupFilePath starts_with Bypass

published 3mo ago modified 2mo ago also EUVD-2026-60374 , GHSA-rqfm-pw34-r7j6

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository notepad-plus-plus/notepad-plus-plus. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
5.1
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

Notepad++ is a free and open-source source code editor. Prior to 8.9.7, Notepad++ validates the backupFilePath attribute from session.xml with std::wstring::starts_with against the expected backup directory without path normalization, allowing parent-directory sequences during snapshot-mode restoration to read an arbitrary user-readable file outside the backup directory into an editor tab. This issue is fixed in version 8.9.7.

Patch / fix

  • notepad-plus-plus notepad++ 8.9.7

Is CVE-2026-52886 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.

Check with Fencer

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-11).

Exploits and checks

  • github.com https://github.com/notepad-plus-plus/notepad-plus-plus/security/advisories/GHSA-rqfm-pw34-r7j6 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
CNA 4.0 5.1 CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/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

  • notepad-plus-plus notepad-plus-plus

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.

The maintainers of notepad-plus-plus/notepad-plus-plus published their own advisory on GitHub. Reviewed sources take precedence over it.

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