CVE-2026-40521
FrontAccounting < 2.4.20 Path Traversal RCE via attachment upload
CVSS Score
8.8
EPSS Score
0.0%
EPSS Percentile
0th
FrontAccounting before 2.4.20 contains a path traversal vulnerability in the attachment upload handler that allows authenticated attackers to execute arbitrary code by uploading files with traversal sequences in the unique_name parameter. Attackers can supply path traversal sequences ../../../shell.php to write files outside the intended attachments directory into the web root, and by uploading PHP files without extension validation, achieve remote code execution as the web server user.
| CWE | CWE-22 |
| Vendor | frontaccounting |
| Product | frontaccounting |
| Published | Jun 29, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Affected Versions
FrontAccounting / FrontAccounting
0 < 2.4.20
References
jivasecurity.com: https://jivasecurity.com/writeups/frontaccounting-rce-attachment-upload-cve-2026-40521 sourceforge.net: https://sourceforge.net/p/frontaccounting/news/2026/04/release-2420/ github.com: https://github.com/FrontAccountingERP/FA/commit/701fea6848da4a02fb83d30f07a9c0473d6b7e33 vulncheck.com: https://www.vulncheck.com/advisories/frontaccounting-path-traversal-rce-via-attachment-upload
Credits
Jiva (JivaSecurity)