CVE-2026-49453: Input Validation Flaw (CVSS 7)

Description

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, Joplin accepts synchronized resource metadata whose id or file_extension contains parent-directory or path-separator characters. BaseItem.unserialize() stores the unvalidated fields, resourceFilename() concatenates them into a destination path, and ResourceFetcher writes the attacker-controlled resource blob outside the resource directory during background synchronization. An attacker with write access to a configured sync target or shared notebook can create or overwrite files at an attacker-chosen existing path without user interaction. This issue is fixed in versions 3.6.15 and 3.7.2.

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CVSS v3.1 Score

7.0

HIGH

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:L

EPSS — Exploit Prediction

0.0041

Probability of exploitation

0.33%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-20 Improper Input Validation

CWE-22 Path Traversal

References

Other References

https://github.com/laurent22/joplin/commit/18e0b08c282c89ae51612c4eff67af2a45ff5163 https://github.com/laurent22/joplin/commit/50518073740c4501058e366300b42c2f1925cb05 https://github.com/laurent22/joplin/pull/15540 https://github.com/laurent22/joplin/pull/15672 https://github.com/laurent22/joplin/security/advisories/GHSA-r24r-gp6h-cwgf https://github.com/laurent22/joplin/security/advisories/GHSA-r24r-gp6h-cwgf

Frequently Asked Questions

What is CVE-2026-49453? +

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, Joplin accepts synchronized resource metadata whose id or file_extension contains parent-directory or path-separator characters. BaseItem.unserialize() stores the unvalidated fields, resourceFilename() concatenates them into a destination path, and ResourceFetcher writes the attacker-controlled resource blob outside the resource directory during background synchronization. An attacker with write access to a configured sync target or shared notebook can create or overwrite files at an attacker-chosen existing path without user interaction. This issue is fixed in versions 3.6.15 and 3.7.2. It has a CVSS v3.1 base score of 7.0 (HIGH).

How severe is CVE-2026-49453? +

CVE-2026-49453 has a CVSS v3.1 score of 7.0 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0041, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-49453? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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