Torproject Tor vulnerabilities, page 2
48 vulnerabilities
Known vulnerabilities in Torproject Tor, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
CVE-2020-8516debiantor+1
EPSS score2.50%
The daemon in Tor through 0.4.1.8 and 0.4.2.x through 0.4.2.6 does not verify that a rendezvous node is known before attempting to connect to it, which might make it easier for remote attackers to discover circuit information. NOTE: The network team of Tor claims this is an intended behavior and not a vulnerabilityCVE-2014-5117debiantor+4EPSS score2.10%
Tor before 0.2.4.23 and 0.2.5 before 0.2.5.6-alpha maintains a circuit after an inbound RELAY_EARLY cell is received by a client, which makes it easier for remote attackers to conduct traffic-confirmation attacks by using the pattern of RELAY and RELAY_EARLY cells as a means of communicating information about hidden service names.CVE-2022-33903debiantor+6EPSS score1.34%
Tor 0.4.7.x before 0.4.7.8 allows a denial of service via the wedging of RTT estimation.CVE-2012-2250debiantor+1EPSS score1.29%
Tor before 0.2.3.24-rc allows remote attackers to cause a denial of service (assertion failure and daemon exit) by performing link protocol negotiation incorrectly.CVE-2012-2249debiantor+1EPSS score1.29%
Tor before 0.2.3.23-rc allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a renegotiation attempt that occurs after the initiation of the V3 link protocol.CVE-2012-4419debiantor+1EPSS score2.16%
The compare_tor_addr_to_addr_policy function in or/policies.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.21-rc, allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a zero-valued port field that is not properly handled during policy comparison.CVE-2012-4922debiantor+1EPSS score2.23%
The tor_timegm function in common/util.c in Tor before 0.2.2.39, and 0.2.3.x before 0.2.3.22-rc, does not properly validate time values, which allows remote attackers to cause a denial of service (assertion failure and daemon exit) via a malformed directory object, a different vulnerability than CVE-2012-4419.CVE-2012-5573debiantor+2EPSS score3.15%
The connection_edge_process_relay_cell function in or/relay.c in Tor before 0.2.3.25 maintains circuits even if an unexpected SENDME cell arrives, which might allow remote attackers to cause a denial of service (memory consumption or excessive cell reception rate) or bypass intended flow-control restrictions via a RELAY_COMMAND_SENDME command.CVE-2017-16541debianfirefox-esr+11EPSS score3.66%
Tor Browser before 7.0.9 on macOS and Linux allows remote attackers to bypass the intended anonymity feature and discover a client IP address via vectors involving a crafted web site that leverages file:// mishandling in Firefox, aka TorMoil. NOTE: Tails is unaffected.CVE-2017-0376debiantor+4EPSS score2.18%
The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the connection_edge_process_relay_cell function via a BEGIN_DIR cell on a rendezvous circuit.CVE-2017-0380debiantor+4EPSS score1.54%
The rend_service_intro_established function in or/rendservice.c in Tor before 0.2.8.15, 0.2.9.x before 0.2.9.12, 0.3.0.x before 0.3.0.11, 0.3.1.x before 0.3.1.7, and 0.3.2.x before 0.3.2.1-alpha, when SafeLogging is disabled, allows attackers to obtain sensitive information by leveraging access to the log files of a hidden service, because uninitialized stack data is included in an error message about construction of an introduction point circuit.CVE-2017-0375torprojecttorEPSS score2.61%
The hidden-service feature in Tor before 0.3.0.8 allows a denial of service (assertion failure and daemon exit) in the relay_send_end_cell_from_edge_ function via a malformed BEGIN cell.CVE-2017-0377torprojecttorEPSS score2.45%
Tor 0.3.x before 0.3.0.9 has a guard-selection algorithm that only considers the exit relay (not the exit relay's family), which might allow remote attackers to defeat intended anonymity properties by leveraging the existence of large families.CVE-2019-8955debiantor+5EPSS score4.57%
In Tor before 0.3.3.12, 0.3.4.x before 0.3.4.11, 0.3.5.x before 0.3.5.8, and 0.4.x before 0.4.0.2-alpha, remote denial of service against Tor clients and relays can occur via memory exhaustion in the KIST cell scheduler.CVE-2026-77641debiantor+2EPSS score0.35%
tor before 0.4.9.9 was prone to a NULL write after free when sending a CONFLUX_SWITCH cell fails. The return value of relay_send_command_from_edge() was ignored, so a send failure (which calls circuit_mark_for_close() and removes the leg via cfx_del_leg()) would go undetected, causing the caller to write to the now-freed current leg and resulting in a crash. This is TROVE-2026-017.CVE-2026-77584debiantor+2EPSS score0.25%
Tor before 0.4.9.10 did not reject a CONFLUX_LINK cell that arrives on a circuit which already has attached streams. A malicious client could send a RELAY_COMMAND_BEGIN before the CONFLUX_LINK on the same circuit, attaching an exit stream that would later end up orphan leaving a dangling circuit back-pointer and a use-after-free (UAF) when the circuit is freed. This is TROVE-2026-025.CVE-2026-77639debiantor+2EPSS score0.39%
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.CVE-2026-77640debiantor+2EPSS score0.38%
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.CVE-2026-77638debiantor+2EPSS score0.30%
Tor before 0.4.9.11 is prone to a race condition where in just the right circumstances a rendezvous point could man-in-the-middle (impersonate) the onion service that the client was trying to reach.CVE-2026-77587debiantor+2EPSS score0.40%
Tor before 0.4.9.11 is prone to a use-after-free (and potential double free) of a conflux object when a recovery leg revives a conflux set whose last linked leg has already been closed. A malicious exit node could use this to crash a client. This is TROVE-2026-026.