8.6.3

Update urgency: SECURITY: There are security fixes in the release.

Security fixes

• (CVE-2026-23479) Use-After-Free in unblock client flow may lead to Remote Code Execution.
• (CVE-2026-25243) Invalid memory access in RESTORE may lead to Remote Code Execution
• (CVE-2026-23631) Lua Use-After-Free may lead to remote code execution
• (CVE-2026-25588) Invalid memory access in RESTORE may lead to Remote Code Execution (Time Series)
• (CVE-2026-25589) Invalid memory access in RESTORE may lead to Remote Code Execution (Probabilistic)

Bug fixes

• SUBSCRIBE, PSUBSCRIBE, SSUBSCRIBE: crash on OOM (RED-167788)
• CONFIG SET: some settings allow invalid characters (RED-167787)
• SCRIPT DEBUG: potential crash on scripts (RED-175507)
• VADD: crash or buffer overflow on large REDUCE value (RED-170921)
• VSET: crash on huge allocations (MOD-12678)
• Potential crash on disconnections and TLS failures (Time Series) (MOD-14850)
• RediSearch/RediSearch#8745 Crash when many keys receive expirations under heavy TTL activity (MOD-14500)
• RediSearch/RediSearch#8848 HNSW vector index memory growth under high-churn workloads until shard restart (MOD-13761)
• RediSearch/RediSearch#8205, RediSearch/RediSearch#8259 FT.HYBRID VSIM RANGE + FILTER incorrectly returns zero results (MOD-12370, MOD-13884)
• RediSearch/RediSearch#9182 FT.PROFILE HYBRID returns an empty reply (MOD-14778)
• RediSearch/RediSearch#8129, RediSearch/RediSearch#8140 FT.PROFILE reports an incorrect shard total profile time (MOD-13735, MOD-13181)
• RediSearch/RediSearch#9047 FT.PROFILE output is inconsistent when a profiled value is missing (MOD-10560)
• RediSearch/RediSearch#8791 FT.EXPLAIN does not lock, causing a race with concurrent index changes (MOD-14461)
• RediSearch/RediSearch#8382 Crash when indexing negative zero (-0.0) (MOD-13904)
• RediSearch/RediSearch#8590 FILTER returns inconsistent results with multiple indexes sharing field aliases (MOD-14063)
• RediSearch/RediSearch#8660 FILTER behavior depends on property order in the expression (MOD-14065)
• RediSearch/RediSearch#8593 Filter expressions are evaluated for indexes that do not match the document type (MOD-14064)
• RediSearch/RediSearch#8591 Documents are inconsistently included or excluded depending on the indexing path taken (MOD-13948)
• RediSearch/RediSearch#8589 RENAME notification handler loads the wrong key, causing stale index entries after a rename (MOD-14328)
• RediSearch/RediSearch#9012 PERSIST and HPERSIST notifications are not reflected in index expiration tracking (MOD-14800)
• RediSearch/RediSearch#9079 FT.SPELLCHECK treats PARAMS placeholders as literal terms instead of resolving them (MOD-10596)
• RediSearch/RediSearch#8462 GC out-of-memory on replica shards leaves the replica in an inconsistent state (MOD-14066)
• RediSearch/RediSearch#9066 Race condition in FT.HYBRID causes intermittent failures under concurrent hybrid query load (MOD-14732)
• RediSearch/RediSearch#8109, RediSearch/RediSearch#8149 Configuration registration omits module parameters, causing them to be unexposed or misapplied (RED-171841)
• RediSearch/RediSearch#9163 Crash on FT.SEARCH when topology validation fails (for example, some nodes unreachable) (MOD-14475)
• RediSearch/RediSearch#8395 FT.SEARCH fails with "Query requires unavailable slots" after shard restart or failover (MOD-13828)
• RediSearch/RediSearch#8451 FT.INFO-style output no longer reports zero-index summary data when no indices exist (MOD-14079)
• RediSearch/RediSearch#9078 FT.CREATE now rejects schema definitions with invalid option combinations at creation time (MOD-14655)
• RediSearch/RediSearch#8051, RediSearch/RediSearch#8114 Crash diagnostics now include the IndexSpec of the index the failing thread was working on (MOD-7574)

Metrics

• RediSearch/RediSearch#8210, RediSearch/RediSearch#8231 FT.PROFILE: added queue time tracking (MOD-13602)