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openSUSE-SU-2026:20889-1

Security update for tor

No score

openSUSE-SU-2026:20889-1 is a vulnerability with no CVSS score yet, published June 2, 2026. No source lists public exploit code. No source names a fixed version.

What does this mean?
Severity
UnratedNo CVSS score yet
Exploit chance
UnscoredNo EPSS score yet
Exploitation
None knownNot on CISA’s or ENISA’s lists
Fixed in
No fix listedNo source names one

Description

This update for tor fixes the following issues:

Changes in tor:

  • Update to 0.4.9.9
    • Major bugfixes (compression, security):
      • Fix 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. TROVE-2026-022. Fixes bug 41275; bugfix on 0.3.1.1-alpha.
      • Fix 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. TROVE-2026-021. Fixes bug 41274; bugfix on 0.2.6.1-alpha.
    • Major bugfixes (conflux, security):
      • Fix 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. TROVE-2026-017. Fixes bug 41263; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (security, TROVE-2026-019):
      • Avoid out-of-bounds read/write when parsing a consensus or detached signature with unexpected signature digest type. Impact is minor for most Tor roles, but potentially major for directory authorities. Fixes bug 41267; bugfix on 0.2.8.2-alpha.
    • Major bugfixes (client stability, TROVE-2026-013, TROVE-2026-015):
      • Protect against a client-side assert that can happen if a malicious onion service gets the client to load its carefully crafted onion descriptor. Fixes bugs 41259 and 41261; bugfix on 0.3.1.1-alpha.
    • Major bugfixes (code safety):
      • Avoid a dangerous situation in router_find_exact_exit_enclave() where we could have reached an assert if bridges or relays claim an IP address of 0.0.0.0. Fixes bug 41276; bugfix on 0.4.5.1-alpha.
    • Major bugfixes (conflux, shutdown):
      • Fix a use-after-free in the shutdown path when freeing conflux circuits. cfx_add_leg() shares stream list pointers across legs without NULLing the old leg, so circuit_free_all() would free the lists via one leg and then access freed memory via another. TROVE- 2026-016. Fixes bug 41262; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (DNSPort, TROVE-2026-018):
      • Fix a client-side crash that would happen if we decide to stop reading on a RESOLVE request that came from the DNSPort or controller. This crash could happen naturally under heavy load and with poor luck, but since 0.4.7.2-alpha it could be induced by the exit relay via a flow control request. Fixes bug 41265; bugfix on 0.2.0.1-alpha.
    • Major bugfixes (memory safety, TROVE-2026-014):
      • Avoid a heap-use-after-free mistake that can happen in the conflux subsystem, and which can be induced at either the client or the exit relay. Fixes bug 41260; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (onion services, TROVE-2026-020):
      • Avoid a possible divide by zero crash on onion services that have the proof-of-work (PoW) defense enabled. This bug could be hit by extreme bad luck or maybe by the help of an attacker crafting just the right circumstances. Fixes bug 41270; bugfix on 0.4.8.1-alpha.

What each source reports

OSVNo score

Security update for tor

This update for tor fixes the following issues:

Changes in tor:

  • Update to 0.4.9.9
    • Major bugfixes (compression, security):
      • Fix 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. TROVE-2026-022. Fixes bug 41275; bugfix on 0.3.1.1-alpha.
      • Fix 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. TROVE-2026-021. Fixes bug 41274; bugfix on 0.2.6.1-alpha.
    • Major bugfixes (conflux, security):
      • Fix 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. TROVE-2026-017. Fixes bug 41263; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (security, TROVE-2026-019):
      • Avoid out-of-bounds read/write when parsing a consensus or detached signature with unexpected signature digest type. Impact is minor for most Tor roles, but potentially major for directory authorities. Fixes bug 41267; bugfix on 0.2.8.2-alpha.
    • Major bugfixes (client stability, TROVE-2026-013, TROVE-2026-015):
      • Protect against a client-side assert that can happen if a malicious onion service gets the client to load its carefully crafted onion descriptor. Fixes bugs 41259 and 41261; bugfix on 0.3.1.1-alpha.
    • Major bugfixes (code safety):
      • Avoid a dangerous situation in router_find_exact_exit_enclave() where we could have reached an assert if bridges or relays claim an IP address of 0.0.0.0. Fixes bug 41276; bugfix on 0.4.5.1-alpha.
    • Major bugfixes (conflux, shutdown):
      • Fix a use-after-free in the shutdown path when freeing conflux circuits. cfx_add_leg() shares stream list pointers across legs without NULLing the old leg, so circuit_free_all() would free the lists via one leg and then access freed memory via another. TROVE- 2026-016. Fixes bug 41262; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (DNSPort, TROVE-2026-018):
      • Fix a client-side crash that would happen if we decide to stop reading on a RESOLVE request that came from the DNSPort or controller. This crash could happen naturally under heavy load and with poor luck, but since 0.4.7.2-alpha it could be induced by the exit relay via a flow control request. Fixes bug 41265; bugfix on 0.2.0.1-alpha.
    • Major bugfixes (memory safety, TROVE-2026-014):
      • Avoid a heap-use-after-free mistake that can happen in the conflux subsystem, and which can be induced at either the client or the exit relay. Fixes bug 41260; bugfix on 0.4.8.1-alpha.
    • Major bugfixes (onion services, TROVE-2026-020):
      • Avoid a possible divide by zero crash on onion services that have the proof-of-work (PoW) defense enabled. This bug could be hit by extreme bad luck or maybe by the help of an attacker crafting just the right circumstances. Fixes bug 41270; bugfix on 0.4.8.1-alpha.
Record
openSUSE-SU-2026:20889-1
Updated
2026-11-02

History

History
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