Description
Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022.
Published: 2026-08-20
Score: 5.3 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Fri, 21 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 21 Aug 2026 01:30:00 +0000

Type Values Removed Values Added
Title Compression Bomb Bypass Vulnerability in Tor

Thu, 20 Aug 2026 21:15:00 +0000

Type Values Removed Values Added
Description Tor before 0.4.9.9 was prone to a compression bomb bypass where an attacker could concatenate many gzip or zlib sub-streams, each just under the per-stream detection threshold, to avoid the compression bomb check entirely. This is TROVE-2026-022.
First Time appeared Torproject
Torproject tor
Weaknesses CWE-420
CPEs cpe:2.3:a:torproject:tor:*:*:*:*:*:*:*:*
Vendors & Products Torproject
Torproject tor
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-08-21T20:08:38.672Z

Reserved: 2026-08-20T20:57:49.855Z

Link: CVE-2026-77639

cve-icon Vulnrichment

Updated: 2026-08-21T20:06:33.105Z

cve-icon NVD

Status : Received

Published: 2026-08-20T21:17:11.233

Modified: 2026-08-21T21:17:07.700

Link: CVE-2026-77639

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T01:15:07Z

Weaknesses