Greetings, We just announced Tor 0.4.9.12: https://forum.torproject.org/t/security-release-0-4-9-12/22096 Note that we are moving to a two weeks release cadence due to the sheer amount of security reports we got. Please upgrade as soon as possible! Here is the ChangeLog: Changes in version 0.4.9.12 - 2026-09-08 Another security release containing several high security fixes reported by the exciting and controversial world of LLMs. One important note is that new protocol versions are recommended for clients and relays (41316). Furthermore, authorities will NOT accept relay descriptor containing TAP keys anymore hence the importance for all relays to upgrade to the latest 0.4.9.x stable version. We very strongly recommend upgrading as soon as possible. o Major bugfixes (security): - Do not purge memory for OOM from within low-level code. Previously, we would handle OOM conditions from within append_cell_to_circuit_queue, which could appear at various places within our call stack, and lead to objects being freed at surprising points in the code, with attendent risk of use-after- free errors. Now we only check for OOM conditions there, and handle them from much higher in the stack. Fixes bugs 41341, 41336, 41326, and 41363; bugfix on 0.2.4.14-alpha. Root-cause fix for TROVE-2026-043. - Fix a bug where a hostile cache could trick a client into falsely believing that certain relays' microdescriptors or router descriptors were unusable. Fixes bug 41358; bugfix on 0.2.6.1-alpha or earlier. Tracked as TROVE-2026-034. - Fix a use-after-free error that could occur if AutomapHostsOnResolve was set. Applications using AutomapHostsOnResolve with IPv4, or with small VirtualAddrNetwork values, are especially vulnerable. Fixes bug 41319; bugfix on 0.2.1.29. Tracked as TROVE-2026-036. - Limit the size of consensus diffs, in bytes and in lines, to prevent a class of memory-based denial-of-service attacks. Fixes bug 41329; bugfix on 0.3.1.1-alpha. This is tracked as TROVE-2026-042. - Negotiate CGO cryptography with every hop that supports it. Previously, we failed to negotiate CGO with hops other than the final hop of a circuit, since we did not enable congestion-control with those hops. Now, we negotiate congestion-control _and_ CGO whenever we can. Fixes bug 41348; bugfix on 0.4.9.3-alpha. Tracked as TROVE-2026-033. - Reject the CC_RESPONSE extension in any handshakes for which congestion control was _not_ requested. Previously, clients would interpret this extension, which could put congestion control into an invalid state, leading to a possible remote crash attack. Fixes bug 41345; bugfix on 0.4.9.3-alpha. Tracked as TROVE-2026-032. - Validate DNS names for complience whenever providing or receiving them from evdns, to limit exposure to a class of application and library bugs. Fixes bug 41320; bugfix on 0.1.1.23. Resolves TROVE-2026-035. o Major bugfixes (conflux, client, stream isolation): - Keep the stream isolation state in sync of a linked conflux set on every leg when attaching new streams. This is TROVE-2026-040. Fixes bug 41325; bugfix on 0.4.8.1-alpha. o Minor feature (authority): - Reject 0.4.8.x series at the authority level. Closes ticket 41234. o Minor features (directory authority): - Authorities now recommend additional protocols for clients and relays. Part of ticket 41316. - Provide a new `AuthDirSupport048Clients` option, which is disabled by default. When this option is disabled, authorities will accept router descriptors that do not contain TAP keys, and will be willing to generate microdescriptors without TAP keys in response to such descriptors. This introduces a new consensus method (36). Part of ticket 41316. o Minor features (fallbackdir): - Regenerate fallback directories generated on September 08, 2026. o Minor features (geoip data): - Update the geoip files to match the IPFire Location Database, as retrieved on 2026/09/08. o Minor features (portability): - Fix seccomp compilation with recent versions of glibc. (Closes ticket 41317.) o Minor bugfixes (controller): - Fix an assert that can happen if a controller requests an HSFETCH naming a relay that has a local descriptor but isn't in the consensus. Fixes bug 41367; bugfix on 0.2.7.1-alpha. o Minor bugfixes (directory authorities): - If two shared-random-value commitments are equal, directory authorities now tie-break by authority identity during the reveal phase. Equal commits could happen if an evil authority republishes another's public commitment (and later its public reveal) as its own. Previously the two tied entries could cause honest authorities to disagree about the resulting SRV. Fixes bug 41356; bugfix on 0.2.9.1-alpha. o Removed features: - Tor clients no longer accept consensus instructions to downgrade the congestion control algorithm. This is defense-in-depth for issues like 41345. Implements ticket 41361. Cheers! David -- M5tMvg2BsHibEAX/INnzIxZZxnswS6bx2zkY2awF30s=