DocumentationVersion comparison
POSTGRESQL · VERSION COMPARE
All features, fixes, and compatibility notes in this release, with related records from other versions.
Includes changes after the source version through the target. A major version name means its initial release.
From PostgreSQL 9.0 onward: 17 major branches and 352 release notes. Updated 2026-09-26.
Complete release changes
2017-08-10
9.2.22 HistoricalSupport ends 2017-11-09
| CVE / issue | Severity | Fixed version |
|---|---|---|
| CVE-2017-7547 Further restrict visibility of pg_user_mappings.umoptions, to protect passwords stored as user mapping options | 8.5 | 9.2.22 |
| CVE-2017-7486 Further restrict visibility of pg_user_mappings.umoptions, to protect passwords stored as user mapping options | 8.5 | 9.2.21 |
| CVE-2017-7546 Disallow empty passwords in all password-based authentication methods | 8.1 | 9.2.22 |
A dump/restore is not required for those running 9.2.X.
However, if you use foreign data servers that make use of user passwords for authentication, see the first changelog entry below.
Also, if you are upgrading from a version earlier than 9.2.20, see Section E.5.
Changes
Further restrict visibility of pg_user_mappings.umoptions, to protect passwords stored as user mapping options (Noah Misch)
The fix for CVE-2017-7486 was incorrect: it allowed a user to see the options in her own user mapping, even if she did not have USAGE permission on the associated foreign server. Such options might include a password that had been provided by the server owner rather than the user herself. Since information_schema.user_mapping_options does not show the options in such cases, pg_user_mappings should not either. (CVE-2017-7547)
By itself, this patch will only fix the behavior in newly initdb'd databases. If you wish to apply this change in an existing database, you will need to do the following:
Restart the postmaster after adding allow_system_table_mods = true to postgresql.conf. (In versions supporting ALTER SYSTEM, you can use that to make the configuration change, but you'll still need a restart.)
In each database of the cluster, run the following commands as superuser:
SET search_path = pg_catalog;
CREATE OR REPLACE VIEW pg_user_mappings AS
SELECT
U.oid AS umid,
S.oid AS srvid,
S.srvname AS srvname,
U.umuser AS umuser,
CASE WHEN U.umuser = 0 THEN
'public'
ELSE
A.rolname
END AS usename,
CASE WHEN (U.umuser <> 0 AND A.rolname = current_user
AND (pg_has_role(S.srvowner, 'USAGE')
OR has_server_privilege(S.oid, 'USAGE')))
OR (U.umuser = 0 AND pg_has_role(S.srvowner, 'USAGE'))
OR (SELECT rolsuper FROM pg_authid WHERE rolname = current_user)
THEN U.umoptions
ELSE NULL END AS umoptions
FROM pg_user_mapping U
LEFT JOIN pg_authid A ON (A.oid = U.umuser) JOIN
pg_foreign_server S ON (U.umserver = S.oid);
Do not forget to include the template0 and template1 databases, or the vulnerability will still exist in databases you create later. To fix template0, you'll need to temporarily make it accept connections. In PostgreSQL 9.5 and later, you can use
ALTER DATABASE template0 WITH ALLOW_CONNECTIONS true;
and then after fixing template0, undo that with
ALTER DATABASE template0 WITH ALLOW_CONNECTIONS false;
In prior versions, instead use
UPDATE pg_database SET datallowconn = true WHERE datname = 'template0'; UPDATE pg_database SET datallowconn = false WHERE datname = 'template0';
Finally, remove the allow_system_table_mods configuration setting, and again restart the postmaster.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Disallow empty passwords in all password-based authentication methods (Heikki Linnakangas)
libpq ignores empty password specifications, and does not transmit them to the server. So, if a user's password has been set to the empty string, it's impossible to log in with that password via psql or other libpq-based clients. An administrator might therefore believe that setting the password to empty is equivalent to disabling password login. However, with a modified or non-libpq-based client, logging in could be possible, depending on which authentication method is configured. In particular the most common method, md5, accepted empty passwords. Change the server to reject empty passwords in all cases. (CVE-2017-7546)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
On Windows, retry process creation if we fail to reserve the address range for our shared memory in the new process (Tom Lane, Amit Kapila)
This is expected to fix infrequent child-process-launch failures that are probably due to interference from antivirus products.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix low-probability corruption of shared predicate-lock hash table in Windows builds (Thomas Munro, Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Avoid logging clean closure of an SSL connection as though it were a connection reset (Michael Paquier)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Prevent sending SSL session tickets to clients (Tom Lane)
This fix prevents reconnection failures with ticket-aware client-side SSL code.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix code for setting tcp_keepalives_idle on Solaris (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix statistics collector to honor inquiry messages issued just after a postmaster shutdown and immediate restart (Tom Lane)
Statistics inquiries issued within half a second of the previous postmaster shutdown were effectively ignored.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Ensure that the statistics collector's receive buffer size is at least 100KB (Tom Lane)
This reduces the risk of dropped statistics data on older platforms whose default receive buffer size is less than that.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix possible creation of an invalid WAL segment when a standby is promoted just after it processes an XLOG_SWITCH WAL record (Andres Freund)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix SIGHUP and SIGUSR1 handling in walsender processes (Petr Jelinek, Andres Freund)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix unnecessarily slow restarts of walreceiver processes due to race condition in postmaster (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix cases where an INSERT or UPDATE assigns to more than one element of a column that is of domain-over-array type (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Move autogenerated array types out of the way during ALTER ... RENAME (Vik Fearing)
Previously, we would rename a conflicting autogenerated array type out of the way during CREATE; this fix extends that behavior to renaming operations.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Ensure that ALTER USER ... SET accepts all the syntax variants that ALTER ROLE ... SET does (Peter Eisentraut)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Properly update dependency info when changing a datatype I/O function's argument or return type from opaque to the correct type (Heikki Linnakangas)
CREATE TYPE updates I/O functions declared in this long-obsolete style, but it forgot to record a dependency on the type, allowing a subsequent DROP TYPE to leave broken function definitions behind.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Reduce memory usage when ANALYZE processes a tsvector column (Heikki Linnakangas)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix unnecessary precision loss and sloppy rounding when multiplying or dividing money values by integers or floats (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Tighten checks for whitespace in functions that parse identifiers, such as regprocedurein() (Tom Lane)
Depending on the prevailing locale, these functions could misinterpret fragments of multibyte characters as whitespace.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Use relevant #define symbols from Perl while compiling PL/Perl (Ashutosh Sharma, Tom Lane)
This avoids portability problems, typically manifesting as a "handshake" mismatch during library load, when working with recent Perl versions.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
In psql, fix failure when COPY FROM STDIN is ended with a keyboard EOF signal and then another COPY FROM STDIN is attempted (Thomas Munro)
This misbehavior was observed on BSD-derived platforms (including macOS), but not on most others.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix pg_dump to not emit invalid SQL for an empty operator class (Daniel Gustafsson)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix pg_dump output to stdout on Windows (Kuntal Ghosh)
A compressed plain-text dump written to stdout would contain corrupt data due to failure to put the file descriptor into binary mode.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix pg_get_ruledef() to print correct output for the ON SELECT rule of a view whose columns have been renamed (Tom Lane)
In some corner cases, pg_dump relies on pg_get_ruledef() to dump views, so that this error could result in dump/reload failures.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix dumping of function expressions in the FROM clause in cases where the expression does not deparse into something that looks like a function call (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix pg_basebackup output to stdout on Windows (Haribabu Kommi)
A backup written to stdout would contain corrupt data due to failure to put the file descriptor into binary mode.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix pg_upgrade to ensure that the ending WAL record does not have wal_level = minimum (Bruce Momjian)
This condition could prevent upgraded standby servers from reconnecting.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Always use -fPIC, not -fpic, when building shared libraries with gcc (Tom Lane)
This supports larger extension libraries on platforms where it makes a difference.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix unescaped-braces issue in our build scripts for Microsoft MSVC, to avoid a warning or error from recent Perl versions (Andrew Dunstan)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
In MSVC builds, handle the case where the openssl library is not within a VC subdirectory (Andrew Dunstan)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
In MSVC builds, add proper include path for libxml2 header files (Andrew Dunstan)
This fixes a former need to move things around in standard Windows installations of libxml2.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
In MSVC builds, recognize a Tcl library that is named tcl86.lib (Noah Misch)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
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The comparison follows PostgreSQL release notes from just after the source through the target version. For a major upgrade, maintenance releases from each older branch are included only up to the next major release date, and never after the target date. A major version such as 18 means its initial release, 18.0. Previews and development snapshots are labeled separately.
Entries come from the original English manuals. Release coverage and commit evidence are verified against upstream sources. Every entry retains its complete explanation and source link. Categories aid browsing; read the full notes for impact, conditions, and migration steps.
Fixes can be backported to several branches. Confirmed duplicates are merged conservatively, with every branch explanation retained. A note describing several independent fixes is excluded only when all are already present in the source. Major-release features remain distinct from related maintenance patches unless their complete original descriptions match. Uncertain matches are retained. This is a release-note history, not an exhaustive comparison of compiled binaries.
CVE results are calculated independently from the PostgreSQL security registry and vulnerability records. A CVE counts as gained protection only when the source is affected and the target is fixed or unaffected. Remaining vulnerabilities are listed separately. Security entries and distinct CVEs are counted separately.
Interaction inspired by pgversions.com and pgversionreport. Content comes from PostgreSQL release notes. See the release notes archive.