CVE-2026-55195

HIGH

8.7

CVSS v4

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.

CWE-409

How to fix

Remediation Available

py7zrDebian

Fixed in:1.1.3+dfsg-1CVE-2026-55195

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v4 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Impact

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

Exploit Intelligence

0.21%probability of exploitation in 30 days

11thpercentile

Low risk: more likely to be exploited than 11% of all known CVEs.

References

Other references3

Related Vulnerabilities

Other CWE-409 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2026-49975	High	7.5	28%	-	Fix
CVE-2026-21441	High	7.5	2.7%	-	Fix
CVE-2024-43499	High	7.5	2.6%	-	Fix
CVE-2024-28180	Medium	4.3	2.0%	-	Fix
CVE-2017-16129	Medium	5.9	1.8%	-	Fix
CVE-2022-29225	High	7.5	1.5%	-	Fix

Common questions

How do I fix CVE-2026-55195?

Upgrade py7zr on debian unstable to 1.1.3+dfsg-1 or later.

Is CVE-2026-55195 being actively exploited?

Not that we know of. CVE-2026-55195 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.21% is the estimated probability that it will be exploited in the next 30 days. That is higher than 11% of all scored CVEs.

How severe is CVE-2026-55195?

CVE-2026-55195 has a CVSS v4 base score of 8.7, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-55195 affect?

Published advisories record a fix for py7zr (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-10.