Unprotected Alternate Channel Affecting tor package, versions <0.4.9.9-1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-ECHOLATEST-TOR-19166215
- published22 Aug 2026
- disclosed20 Aug 2026
Introduced: 20 Aug 2026
NewCVE-2026-77639 (opens in a new tab)How to fix?
Upgrade Echo:latest tor to version 0.4.9.9-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream tor package and not the tor package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.