Stack-Based Buffer Overflow in FortiOS 6.4-7.6.3 via Crafted Packets
CVE-2025-53843 Published on November 18, 2025
A stack-based buffer overflow vulnerability in Fortinet FortiOS 7.6.0 through 7.6.3, FortiOS 7.4.0 through 7.4.8, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4 all versions allows attacker to execute unauthorized code or commands via specially crafted packets
Vulnerability Analysis
CVE-2025-53843 can be exploited with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is a Stack Overflow Vulnerability?
A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
CVE-2025-53843 has been classified to as a Stack Overflow vulnerability or weakness.
Products Associated with CVE-2025-53843
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Affected Versions
Fortinet FortiOS:- Version 7.6.0, <= 7.6.3 is affected.
- Version 7.4.0, <= 7.4.8 is affected.
- Version 7.2.0, <= 7.2.12 is affected.
- Version 7.0.0, <= 7.0.18 is affected.
- Version 6.4.0, <= 6.4.16 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.