CVE-2026-78209

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.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.41% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 34.9% of scored records. A rank, not a probability.

NVD base score

8.4 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-10-14.

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.

Published

2026-08-24 00:30Z2 MO AGO

Last updated

2026-08-29 11:47Z2 MO AGO

Reserved

2026-08-24

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

High (CVSS 8.4)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N

Weaknesses

• CWE-1236Improper Neutralization of Formula Elements in a CSV FileBase

Data version

5.2

Document digest

8c81f69670db0569d8be1af21ebeb92e36b9c0fbd78dcd98c588b7c748e790a4

• github.comhttps://github.com/exceljs/exceljsproduct
• github.comGitHub Security Advisory (GHSA-9wxc-4rhw-hfrw)https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-9wxc-4rhw-hfrwthird-party-advisory
• github.comhttps://github.com/exceljs/exceljs/blob/v4.4.0/lib/csv/csv.js#L109-L182technical-description
• www.vulncheck.comVulnCheck Advisory: exceljs through 4.4.0 CSV Formula Injection via Unescaped Cell Valueshttps://www.vulncheck.com/advisories/exceljs-through-csv-formula-injection-via-unescaped-cell-valuesthird-party-advisory