How severe is CVE-2026-55195?

CVE-2026-55195 has a CVSS 4.0 base score of 8.7, rated high severity.

Is CVE-2026-55195 being actively exploited?

It is not currently listed in CISA's Known Exploited Vulnerabilities catalog, and no EPSS exploit-prediction score is available yet.

How do I fix CVE-2026-55195?

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-2026-55195 published?

CVE-2026-55195 was published on 2026-07-08.

CVE-2026-55195

CVE-2026-55195 is a high-severity vulnerability with a CVSS 4.0 base score of 8.7. The underlying weakness is classified as CWE-409.

Key facts

Severity: High (CVSS 4.0 base score 8.7)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-409
Published: 2026-07-08
Last modified: 2026-07-08

Description

py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr's Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.

Frequently asked questions

What is CVE-2026-55195?: py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, py7zr's Worker.decompress() extracted archive entries without tracking total decompressed size, allowing a crafted .7z file such as a 15.6 KB archive that expands to 100 MB to exhaust disk or memory before extraction completes. This issue is fixed in version 1.1.3.
How severe is CVE-2026-55195?: CVE-2026-55195 has a CVSS 4.0 base score of 8.7, rated high severity.
Is CVE-2026-55195 being actively exploited?: It is not currently listed in CISA's Known Exploited Vulnerabilities catalog, and no EPSS exploit-prediction score is available yet.
How do I fix CVE-2026-55195?: 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-2026-55195 published?: CVE-2026-55195 was published on 2026-07-08.

References

Other CWE-409 vulnerabilities

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…
CVE-2026-49755 — High (CVSS 8.2): Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in wojtekmach Req allows…
CVE-2026-48594 — High (CVSS 8.2): Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in elixir-tesla tesla allows a denial of…
CVE-2026-43970 — High (CVSS 8.2): Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in ninenines cowlib allows…
CVE-2026-44160 — High (CVSS 7.5): Fluentd collects events from various data sources and writes them to files, RDBMS, NoSQL, IaaS, SaaS, Hadoop and so on.…

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