How severe is CVE-2026-78206?

CVE-2026-78206 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-78206 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-78206?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-78206 published?

CVE-2026-78206 was published on 2026-08-24 and last updated on 2026-08-31.

CVE-2026-78206

CVE-2026-78206 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-409.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 1% (48th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-409
Published: 2026-08-24
Last modified: 2026-08-31

Description

exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.

Frequently asked questions

What is CVE-2026-78206?: exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing denial of service.
How severe is CVE-2026-78206?: CVE-2026-78206 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-78206 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (48th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-78206?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-78206 published?: CVE-2026-78206 was published on 2026-08-24 and last updated on 2026-08-31.

References

Other CWE-409 vulnerabilities

CVE-2026-68911 — High (CVSS 8.7): Nicotine+ is a graphical client for the Soulseek peer-to-peer network. Prior to version 3.3.11, a modified remote…
CVE-2026-77620 — High (CVSS 8.7): Vector is a high-performance observability data pipeline. From 0.15.0 until 0.57.0, the logstash source feeds each…
CVE-2026-62963 — High (CVSS 8.7): Centrifugo is an open-source scalable real-time messaging server. Prior to 6.8.4, Centrifugo unidirectional WebSocket…
CVE-2026-55195 — High (CVSS 8.7): py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and…
CVE-2026-53430 — High (CVSS 8.7): Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-grpc grpc…
CVE-2026-44697 — High (CVSS 8.6): Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.17, a remote, unauthenticated…

Browse all CWE-409 vulnerabilities →