2026-02 Regression Fixes

The PostgreSQL Global Development Group is planning for an out-of-cycle release on February 26, 2026 due to regressions introduced in the February 12, 2026 update release, which included releases 18.2, 17.8, 16.12, 15.16, and 14.21. This wiki page provides additional details on the regressions and links to the fixes, in case you wish to apply the fixes ahead of this release.

substring() function raises an error "invalid byte sequence for encoding" on non-ASCII text values if the source of that value is a database column

The fix for CVE-2026-2006, which closed a vulnerability in the database server, introduced a regression causing substring() to improperly return an error on multi-byte (non-ASCII) text values if the source of that value was a database column.

• Thread: https://postgr.es/m/19406-9867fddddd724fca@postgresql.org
• Fixes
  • PostgreSQL 18: 6e045e1a6e3f1a55d3d246f8258f3316410b26f6
  • PostgreSQL 17: 5d5232bc38d36a30b569396f15e5a22cd6ee529b
  • PostgreSQL 16: bdfb372280bc507239a02c0a060f0f51ebd41fa1
  • PostgreSQL 15: a20eb248c51ad6741bbbb3b3bac103d5788bd4f5
  • PostgreSQL 14: 14b1fd6176cb9353846deff607e5dfad09eb5b23

A standby may halt and return an error "could not access status of transaction"

• Thread: https://postgr.es/m/CACV2tSw3VYS7d27ftO_cs%2BaF3M54%2BJwWBbqSGLcKoG9cvyb6EA%40mail.gmail.com
• Fixes
  • PostgreSQL 18: 817f74600d0d015309596762c9e4a07e0ac8fdbf
  • PostgreSQL 17: 4a36c89f1657e0c159a1dcef18f5da4f2cc9348f
  • PostgreSQL 16: 23064542f8bdcbc4b6a513cac8ceed67c0d2336e
  • PostgreSQL 15: 899de38d8f3b519e7fd5b2acf580d1c9282ee6f1
  • PostgreSQL 14: 547a8aaa7d4fffd686c75b1e00b1c11c0980aabc