CVE-2026-77639
Last modified
CVE-2026-77639 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. EPSS estimates a 0.25% chance of exploitation in the next 30 days.
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness Enumeration
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| torproject | Tor | >= 0.3.1.1-alpha, < 0.4.9.9 |
References
Timeline
- Published
- Last Modified
- Status
- Received
Frequently Asked Questions
What is CVE-2026-77639?
How severe is CVE-2026-77639?
How do I fix CVE-2026-77639?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-77611SeaweedFS is a distributed storage system for files and blob…7.1
- CVE-2026-7762A heap-based buffer overflow vulnerability in the dot11ah.ko…9.8
- CVE-2026-7763A heap-based buffer overflow vulnerability in the morse.ko H…9.8
- CVE-2026-77634CakePHP is a rapid development framework for PHP. Prior to v…8.2
- CVE-2026-77635CakePHP is a rapid development framework for PHP. Prior to v…9.2
- CVE-2026-77638Tor before 0.4.9.11 is prone to a race condition where in ju…8.9
- CVE-2026-7764An out-of-bounds read vulnerability in the morse.ko HaLow Wi…6.8
- CVE-2026-77640tor before 0.4.9.9 was prone to an infinite loop when decomp…3.7
- CVE-2026-77641tor before 0.4.9.9 was prone to a NULL write after free when…6.5
- CVE-2026-77642tor before 0.4.9.9 was prone to an out-of-bounds write when …7.5
- CVE-2026-77643A cross-site scripting vulnerability in queryparser/termgen…4.4
- CVE-2026-77644A critical bypass access control vulnerability has been repo…9.3
Are you affected by CVE-2026-77639?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST