CVE-2026-55195

HIGHPre-NVD 8.78.7—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 75% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
8.7EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.7Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
70
EG Risk 70/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity87% × 45%
Exploitation40% × 40%
Automatability100% × 15%
EPSS PROB
0.3%
EPSS %ILE
23rd
KEV
Not listed

Published

June 19, 2026

Last Modified

July 10, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_commit, github_release.
github_release Patch Available

Release version 1.1.3: Fix multiple vulnerabilities

Patch available: miurahr/py7zr v1.1.3

https://github.com/miurahr/py7zr/releases/tag/v1.1.3
github_commit Patch Available

commit 28faf107b643 (miurahr/py7zr)

Patch available: miurahr/py7zr v1.1.3 (contains commit 28faf107b643)

https://github.com/miurahr/py7zr/commit/28faf107b64374fa5a02bfb93aa2024e281ca97b
githubMentions a patch (unverified)🟡 PoC Available

py7zr <= 1.1.2: Decompression bomb (zip bomb) denial of service via unchecked extraction size · Advisory · miurahr/py7zr · GitHub

https://github.com/miurahr/py7zr/security/advisories/GHSA-gjrg-mpp7-g774

Vendor Advisories for CVE-2026-55195(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
py7zr0.11.3+dfsg-1 ... 1.1.3+dfsg-1 (27 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
py7zr0.11.3+dfsg-5 ... 1.1.3+dfsg-4 (25 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
py7zr0.22.0+dfsg-1 ... 1.1.3+dfsg-4 (18 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
py7zr0.22.0+dfsg-1 ... 1.1.2-1+really1.1.0+dfsg-2 (14 versions)
  • every version up to 1.1.3+dfsg-1: fixed in 1.1.3+dfsg-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
py7zr0.0.3 ... 1.1.2 (164 versions)
  • every version up to 1.1.3: fixed in 1.1.3
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 28× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 120 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
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  1. 2026-09-13 13:01 UTCEG score recompute
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Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-55195?
CVE-2026-55195 is a high vulnerability published on June 19, 2026. 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…
When was CVE-2026-55195 disclosed?
CVE-2026-55195 was first published on June 19, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55195 actively exploited?
CVE-2026-55195 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (23rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55195?
CVE-2026-55195 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55195?
A fix for CVE-2026-55195 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55195 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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