CVE-2021-26642: XpressEngine file upload vulnerability

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-01-20 · updated 2026-06-17
Weakness: CWE-434

Description

When uploading an image file to a bulletin board developed with XpressEngine, a vulnerability in which an arbitrary file can be uploaded due to insufficient verification of the file. A remote attacker can use this vulnerability to execute arbitrary code on the server where the bulletin board is running.

Affected products

XpressEngine: before 3.0.14 — fixed in 3.0.14

How to fix

Upgrade to a fixed version: XpressEngine 3.0.14. Check the vendor advisory for mitigations.

References

https://boho.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=67125
https://boho.or.kr/krcert/secNoticeView.do?bulletin_writing_sequence=67125

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