CVE-2026-52886 Notepad++: session.xml backupFilePath starts_with Bypass
Attackers can read arbitrary user-readable files by manipulating session.xml backup paths, affecting Notepad++ users.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-52886?
CVE-2026-52886 is a medium-severity path traversal vulnerability in notepad-plus-plus, published on 17 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-22
Which versions are affected by CVE-2026-52886?
How do I fix CVE-2026-52886?
No fix has been published for CVE-2026-52886 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-52886 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52886 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-rqfm-pw34-r7j6.