7.5

CVE-2025-53843: fortinet fortios Stack-based Buffer Overflow

CVSS: 7.5v3.1HighModified
Published 18-11-2025Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2025-53843 is a high (CVSS 7.5) Stack-based Buffer Overflow vulnerability in fortinet fortios. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 50.7% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
0.66%
0%100%
Low · +0.07 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 18-11-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

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

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.66%

Chance of exploitation in the next 30 days

Percentile

51%

Versus all other CVEs

30-day change

+0.07 pp

From 0.58% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.66%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Fortinet1 product
  • fortios≥ 7.6.0, ≤ 7.6.3 | ≥ 7.4.0, ≤ 7.4.8 | ≥ 7.2.0, ≤ 7.2.12 | ≥ 7.0.0, ≤ 7.0.18 | ≥ 6.4.0, ≤ 6.4.16 | ≥ 6.4.0, < 7.4.9 | ≥ 7.6.0, < 7.6.4

1 vendor · 1 product

References

2 links