4.3

CVE-2026-59840: fortinet fortios Buffer Over-read

CVSS: 4.3v3.1MediumModified
Published 14-07-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-59840 is a medium (CVSS 4.3) Buffer Over-read vulnerability in fortinet fortios. EPSS estimates a 0.31% chance of exploitation in the next 30 days, higher than 22.6% of scored vulnerabilities.

Overall risk
17/100
0100
Low · default modelHow is this calculated?
CVSS score
4.3/10
010
Medium · v3.1 (NVD)
EPSS score
0.31%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

A buffer over-read 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, FortiProxy 7.6.0 through 7.6.5, FortiProxy 7.4.0 through 7.4.13, FortiProxy 7.2 all versions, FortiProxy 7.0 all versions may allow attacker to information disclosure via <insert attack vector here>

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.31%

Chance of exploitation in the next 30 days

Percentile

23%

Versus all other CVEs

30-day change

0.00 pp

From 0.31% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.31%

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

Fortinet4 products
  • fortios≥ 7.2.0, < 7.4.9 | ≥ 7.6.0, ≤ 7.6.2 | ≥ 7.6.0, ≤ 7.6.3 | ≥ 7.4.0, ≤ 7.4.8 | ≥ 7.2.0, ≤ 7.2.13 | ≥ 7.0.0, ≤ 7.0.19 | ≥ 6.4.0, ≤ 6.4.16
  • fortipam1.7.0 | ≥ 1.6.0, ≤ 1.6.2 | ≥ 1.5.0, ≤ 1.5.1 | ≥ 1.4.0, ≤ 1.4.3 | ≥ 1.3.0, ≤ 1.3.1 | 1.2.0 | ≥ 1.1.0, ≤ 1.1.2 | ≥ 1.0.0, ≤ 1.0.3
  • fortiproxy≥ 7.2.0, < 7.4.14 | ≥ 7.6.0, < 7.6.6 | ≥ 7.6.0, ≤ 7.6.5 | ≥ 7.4.0, ≤ 7.4.13 | ≥ 7.2.0, ≤ 7.2.16 | ≥ 7.0.0, ≤ 7.0.23
  • fortiswitchmanager≥ 7.2.0, ≤ 7.2.7 | ≥ 7.0.0, ≤ 7.0.6

1 vendor · 4 products

References

2 links