CVE-2026-77640

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 ZSTREAMEND, causing zlib to return ZBUFERROR with no input remaining, which bufaddcompress mistook for a full output buffer and retried forever. Fixed by...

CVE-2026-77640

Tor before 0.4.9.9 is vulnerable to a denial of service when decompressing a truncated zlib/gzip stream with done=1. The root cause is in buf_add_compress() : a truncated stream never reaches Z_STREAM_END, so zlib returns Z_BUF_ERROR with no input remaining, which the function misinterpreted as a...

CVE-2026-77640: Improper Validation of Specified Quantity in Input

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 ZSTREAMEND, causing zlib to return ZBUFERROR with no input remaining, which bufaddcompress mistook for a full output buffer and retried forever. Fixed by...