CVE-2026-59840
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
02 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
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.31% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 23.9% of scored records. A rank, not a probability.
- NVD base score
- 4.3 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-10-24.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-07-14 15:19Z3 MO AGO
- Last updated
- 2026-10-15 01:23Z14 DAYS AGO
- Reserved
- 2026-07-07
- Assigning CNA
- fortinet
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.1)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
- Weaknesses
- CWE-126Buffer Over-readVariant
- Data version
- 5.2
- Document digest
- 173509a47659cb5256e57e89f2694741db8012b1c7b047e513b9cdc47dd206c9
05 Affected products
06 References
- fortiguard.fortinet.comhttps://fortiguard.fortinet.com/psirt/FG-IR-26-154
- cert-portal.siemens.comhttps://cert-portal.siemens.com/productcert/html/ssa-864900.html
07 Remediation
Upgrade to FortiOS version 7.6.4 or above Upgrade to FortiOS version 7.4.9 or above Fortinet remediated this issue in FortiSASE version 25.4.b and hence customers do not need to perform any action. Upgrade to FortiProxy version 7.6.6 or above Upgrade to FortiProxy version 7.4.14 or above