PostgreSQL full changelog

Changes:
Restrict logical decoding output plugins to the set specified by a new server parameter output_plugin_libraries (Jacob Champion) § §
Previously, a replication user could select any loadable library for logical decoding, allowing exploits of various sorts. To allow locking this down without breaking setups that worked before, introduce a whitelist of allowed output plugins.
By default, only the output plugins shipped as part of PostgreSQL (pgoutput and test_decoding) are included in output_plugin_libraries. Installations that rely on other output plugins must add them after updating the server, for example
output_plugin_libraries = 'pgoutput, test_decoding, my_trusted_decoder'
Additionally, pg_upgrade --check will fail if the output_plugin_libraries parameter on the new cluster does not permit the plugins of logical replication slots on the old cluster, when migrating from versions 17 and later. Make necessary additions to the new cluster's setting before performing pg_upgrade.
The PostgreSQL Project thanks Vladimir Tokarev and Yu Kunpeng for reporting this problem. (CVE-2026-6471)
Fix contrib/pgcrypto's PGP encryption to detect unsupported ciphers (Daniel Gustafsson) § §
Previously, if OpenSSL rejected the requested cipher (for example, because it is running in FIPS mode, or the legacy provider hasn't been loaded), pgcrypto failed to notice the failure and simply XOR'd the non-encrypted block with the plaintext, rendering the “encryption” trivially breakable. This will typically occur with deprecated or non-FIPS cipher algorithms (cipher-algo=blowfish/bf, twofish, cast5, or 3des).
By default, pgcrypto will now fail to decrypt any messages that were affected in this way. To allow retrieval of such data, a new option ignore-cipher-failure has been added to pgp_pub_decrypt() and pgp_sym_decrypt(). Setting ignore-cipher-failure=1 will restore their previous behavior, allowing the faulty encryption wrapper to be stripped off:
pgp_sym_decrypt(encrypted_co

Bug Fixes and Improvements:
This update fixes over 60 bugs that were reported in the last several months. The issues listed below affect PostgreSQL 18. Some of these issues may also affect other supported versions of PostgreSQL.
Fix queries that could return incorrect results when using a nondeterministic collation over a unique index.
Fix loss of deferrability of foreign-key triggers. Previously, a foreign key defined as DEFERRABLE INITIALLY DEFERRED would behave as NOT DEFERRABLE after being set to NOT ENFORCED status and then back to ENFORCED. If you have a foreign key with this problem, after installing this update you can fix it by setting it to NOT ENFORCED and then back to ENFORCED.
Improve the planner's ability to apply partition pruning to more cases.
Fix self-join removal to handle join clauses that are only boolean columns, for example, ON t1.boolcol.
Several fixes around virtual generated columns, including ensuring INSERT ... ON CONFLICT works when EXCLUDED references a virtual generated column.
Report a serialization failure when MERGE encounters a concurrently-updated tuple in "repeatable read" or "serializable" isolation modes.
Fix CREATE TABLE ... LIKE ... INCLUDING STATISTICS for cases where the source table had one or more dropped columns.
Fix WITHOUT OVERLAPS to allow domains.
Disallow making a composite type be a member of itself via a multirange.
Fix sometimes-incorrect results when array_agg(anyarray) executes in parallel.
Prevent bloating during restore of an incremental backup.
Prevent stuck logical replication slot synchronization worker processes from blocking promotion of a standby server.
Make the pg_aios system view pid column show NULL instead of 0 when an entry has no owning process.
Fix cases where pg_stat_replication shows NULL lag even while replication is active.
Correctly display JOIN alias variables that are used in GROUP BY.
If the startup process fails, properly shut down other child processes before exitin

Bug Fixes and Improvements:
This update fixes several bugs that were reported since the previous release. The issues listed below affect PostgreSQL 18. Some of these issues may also affect other supported versions of PostgreSQL.
Fix issue where a standby would halt and return an error "could not access status of transaction".
Fix error where the substring() function would raise an error "invalid byte sequence for encoding" on non-ASCII text values if the source of that value is a database column. This was due to a change introduced for the fix to CVE-2026-2006.
Fix for the strict_word_similarity function in pg_trgm that could lead to incorrect output or crashes. This was due to an oversight in the fix for CVE-2026-2007.
Fix function volatility for json_strip_nulls() and jsonb_strip_nulls() to be immutable, like previous releases, allowing for them to be used in indexes. If you previously upgraded to PostgreSQL 18.0 through 18.2, see the additional steps in the "Updating" section.
Fix for NOT NULL tests in LATERAL UNION ALL subquery that could lead to wrong query output.
Avoid NOT NULL constraints from generating name conflicts with user-written constraints.
Fix pg_stat_get_backend_wait_event() and pg_stat_get_backend_wait_event_type() to report values for auxiliary processes, similar to pg_stat_activity.
Fix casting a composite-type variable to a domain type when returning its value from a PL/pgSQL function.
Fix the hstore binary input function to avoid crashes on input with duplicate keys.

Security Issues:
CVE-2026-2003: PostgreSQL oidvector discloses a few bytes of memory:
CVSS v3.1 Base Score: 4.3:
Supported, Vulnerable Versions: 14 - 18.
Improper validation of type oidvector in PostgreSQL allows a database user to disclose a few bytes of server memory. We have not ruled out viability of attacks that arrange for presence of confidential information in disclosed bytes, but they seem unlikely. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
The PostgreSQL project thanks Altan Birler for reporting this problem.
CVE-2026-2004: PostgreSQL intarray missing validation of type of input to selectivity estimator executes arbitrary code
CVSS v3.1 Base Score: 8.8:
Supported, Vulnerable Versions: 14 - 18.
Missing validation of type of input in PostgreSQL intarray extension selectivity estimator function allows an object creator to execute arbitrary code as the operating system user running the database. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
The PostgreSQL project thanks Daniel Firer, as part of zeroday.cloud, for reporting this problem.
CVE-2026-2005: PostgreSQL pgcrypto heap buffer overflow executes arbitrary code
CVSS v3.1 Base Score: 8.8:
Supported, Vulnerable Versions: 14 - 18.
Heap buffer overflow in PostgreSQL pgcrypto allows a ciphertext provider to execute arbitrary code as the operating system user running the database. Versions before PostgreSQL 18.2, 17.8, 16.12, 15.16, and 14.21 are affected.
The PostgreSQL project thanks Team Xint Code, as part of zeroday.cloud, for reporting this problem.
CVE-2026-2006: PostgreSQL missing validation of multibyte character length executes arbitrary code
CVSS v3.1 Base Score: 8.8:
Supported, Vulnerable Versions: 14 - 18.
Missing validation of multibyte character length in PostgreSQL text manipulation allows a database user to issue crafted queries that achieve a buffer overrun. That suffices to execute arbitrary code as the operating system user runn

Avoid returning duplicate rows from hash right semi-joins.
Avoid possible out-of-memory failures during parallel GIN index build.
Several fixes for BRIN indexes.
Fixes for crashes related to partitioned tables, including one occurring during a recheck.
Avoid duplicating hash partition constraints during DETACH CONCURRENTLY, which previously caused issues during dump/restore or if a parent table is dropped after the DETACH.
Disallow generated columns in partition keys and in COPY ... FROM ... WHERE clauses.
Fix incorrect reporting of replication lag in pg_stat_replication view.
Avoid failures when synchronized_standby_slots references nonexistent replication slots.
Avoid unwanted WAL receiver shutdown when switching from streaming to archive WAL source.
Avoid unnecessary invalidation of logical replication slots.
Correctly handle GROUP BY DISTINCT in PL/pgSQL assignment statements.
Avoid leaking memory when handling a SQL error within PL/Python.
Fix how libpq handles socket-related errors on Windows within its GSSAPI logic.
Fix dumping of non-inherited NOT NULL constraints on inherited table columns.
Ensure consistent ordering of foreign key constraints in the output of pg_dump.
Several fixes for pgbench error handling and reporting.
Fix memory leak in pg_combinebackup.
Allow nonsuperusers with SELECT privileges on a table to use pg_prewarm to prewarm indexes on that table.

Improve behavior of libpq's quoting functions (Andres Freund, Tom Lane) § § §
The changes made for CVE-2025-1094 had one serious oversight: PQescapeLiteral() and PQescapeIdentifier() failed to honor their string length parameter, instead always reading to the input string's trailing null. This resulted in including unwanted text in the output, if the caller intended to truncate the string via the length parameter. With very bad luck it could cause a crash due to reading off the end of memory.
In addition, modify all these quoting functions so that when invalid encoding is detected, an invalid sequence is substituted for just the first byte of the presumed character, not all of it. This reduces the risk of problems if a calling application performs additional processing on the quoted string.
Fix small memory leak in pg_createsubscriber (Ranier Vilela) §
Fix meson build system to correctly detect availability of the bsd_auth.h system header (Nazir Bilal Yavuz) §

Harden PQescapeString and allied functions against invalidly-encoded input strings (Andres Freund, Noah Misch)
Data-quoting functions supplied by libpq now fully check the encoding validity of their input. If invalid characters are detected, they report an error if possible. For the ones that lack an error return convention, the output string is adjusted to ensure that the server will report invalid encoding and no intervening processing will be fooled by bytes that might happen to match single quote, backslash, etc.
The purpose of this change is to guard against SQL-injection attacks that are possible if one of these functions is used to quote crafted input. There is no hazard when the resulting string is sent directly to a PostgreSQL server (which would check its encoding anyway), but there is a risk when it is passed through psql or other client-side code. Historically such code has not carefully vetted encoding, and in many cases it's not clear what it should do if it did detect such a problem.
This fix is effective only if the data-quoting function, the server, and any intermediate processing agree on the character encoding that's being used. Applications that insert untrusted input into SQL commands should take special care to ensure that that's true.
Applications and drivers that quote untrusted input without using these libpq functions may be at risk of similar problems. They should first confirm the data is valid in the encoding expected by the server.
The PostgreSQL Project thanks Stephen Fewer for reporting this problem. (CVE-2025-1094)
Restore auto-truncation of database and user names appearing in connection requests (Nathan Bossart)
This reverts a v17 change that proved to cause trouble for some users. Over-length names should be truncated in an encoding-aware fashion, but for now just return to the former behavior of blind truncation at NAMEDATALEN-1 bytes.
Exclude parallel workers from connection privilege checks and limits (Tom Lane)
Do not check da

New memory management system for VACUUM, which reduces memory consumption and can improve overall vacuuming performance.
New SQL/JSON capabilities, including constructors, identity functions, and the JSON_TABLE() function, which converts JSON data into a table representation.
Various query performance improvements, including for sequential reads using streaming I/O, write throughput under high concurrency, and searches over multiple values in a btree index.
New client-side connection option, sslnegotiation=direct, that performs a direct TLS handshake to avoid a round-trip negotiation.
pg_basebackup now supports incremental backup.
COPY adds a new option, ON_ERROR ignore, that allows a copy operation to continue in the event of an error.
Logical replication enhancements, including:
Failover control
pg_createsubscriber, a utility that creates logical replicas from physical standbys
pg_upgrade now preserves replication slots on both publishers and subscribers

Avoid incorrect results from "Merge Right Anti Join" plans, where if the inner relation is known to have unique join keys, the merge could misbehave when there are duplicated join keys in the outer relation.
Prevent infinite loop in VACUUM.
Fix partition pruning setup during ALTER TABLE DETACH ... PARTITION CONCURRENTLY.
Fix behavior of stable functions that are used as an argument to a CALL statement.
pg_sequence_last_value() now returns NULL instead of throwing an error when called on unlogged sequences on standby servers and on temporary sequences of other sessions.
Fix parsing of ignored operators in websearch_to_tsquery().
Correctly check updatability of view columns targeted by INSERT ... DEFAULT.
Lock owned sequences during ALTER TABLE ... SET LOGGED|UNLOGGED.
Don't throw an error if a queued AFTER trigger no longer exists.
Fix selection of an arbiter index for INSERT ... ON CONFLICT when the desired index has expressions or predicates, for example, through an updatable view.
Refuse to modify a temporary table of another session with ALTER TABLE.
Fix handling of extended statistics on expressions in CREATE TABLE ... LIKE STATISTICS.
Fix failure to recalculate sub-queries generated from MIN() or MAX() aggregates.
Disallow underscores in positional parameters.
Avoid crashing when a JIT-inlined backend function throws an error.
Fix handling of subtransactions of prepared transactions when starting a hot standby server.
Prevent incorrect initialization of logical replication slots.
Fix memory leak in the logical replication WAL sender when publishing changes to a partitioned table whose partitions have row types that are physically different from the table.
Disable creation of stateful TLS session tickets by OpenSSL.
Fix how PL/pgSQL handles integer ranges containing underscores (e.g., FOR i IN 1_001..1_002).
Fix incompatibility between PL/Perl and Perl 5.40.
Several fixes related to recursive PL/Python functions and triggers.
Ensure that pg_restore -l