CVE-20XX-?

CVE-2026-77640

3.7 LOW 0.4% exploit odds Fix listed Other

What it is

tor before 0.4.9.9 was prone to an infinite loop when decompressing a truncated zlib/gzip stream with done=1. A truncated stream never reaches Z_STREAM_END, causing zlib to return Z_BUF_ERROR with no input remaining, which buf_add_compress() mistook for a full output buffer and retried forever. Fixed by returning TOR_COMPRESS_ERROR in that case so the caller can abort cleanly. This is TROVE-2026-021.

At a glance

Exploitability
Can be exploited over the network without logging in. Limited direct impact.
Exploit odds
0.4% chance of exploitation in the next 30 days (EPSS).
Fix
A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

  1. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Details

Published
Last modified
Exploit probability
0.4% · EPSS, next 30 days
Weakness
CWE-1284
Record status
Analyzed

Affected

Attack profile CVSS 3.1 · 3.7

Attack vector
Network
Complexity
High
Privileges needed
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Raw vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L

Meme: I wake up, CVE-2026-77640
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Fix and advisories

References

NVD record · CVE.org record