diff --git a/manifest b/manifest
index 2db4165bdd..70d5220961 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sDEFAULT\sso\sthat\sBLOB\svalues\scast\sto\stext\suse\sthe\sdatabase\sencoding.\n[bugs:/info/2026-10-14T17:33:12Z|Bug\s2026-10-14T17:33:12Z].
-D 2026-10-15T17:36:23.562
+C Avoid\sa\sspurious\scorruption\sreport\sin\ssome\scases\swhen\sprocessing\san\sORDER\sBY\s..\sNULLS\sLAST\squery\sagainst\sa\sWITHOUT\sROWID\stable\sthat\shas\shad\scolumns\sadded\sto\sit\susing\sALTER\sTABLE.\sForum\spost\s[forum:2026-10-15T03:54:19Z\s|\s2026-10-15T03:54:19Z].
+D 2026-10-15T19:07:48.209
 F .fossil-settings/binary-glob 61195414528fb3ea9693577e1980230d78a1f8b0a54c78cf1b9b24d0a409ed6a x
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
@@ -886,7 +886,7 @@ F src/vxworks.h 9d18819c5235b49c2340a8a4d48195ec5d5afb637b152406de95a9436beeaeab
 F src/wal.c 41438914e455bbc42ccff8545eab4c711f91233e480337e44a3d5fdf121fce74
 F src/wal.h c6251cfc1950643a976625ca452e46dc9b466b4f5dd2e85f244f29f79bf68ace
 F src/walker.c d5006d6b005e4ea7302ad390957a8d41ed83faa177e412f89bc5600a7462a014
-F src/where.c 5b68fdbca9b0e636bf84274f3e30a1bafcc91bb8f79590c36647c343669b9952
+F src/where.c b297e416518ffd2b2a7ab91b7f3abadc61f7d95065b3a1e745f2d53df7077d5b
 F src/whereInt.h 5d739acb94bf1fdf6edd502a919e3dcf2d340dda63cc1827304e119ea878f6f3
 F src/wherecode.c 69ff3d0fe8697d2ca482d25c15dfdc08cf8e4605ab5ab297e9d12b3dbc6812fd
 F src/whereexpr.c 76f72a95c5cf0e8a8edb679ca4fb7afa17ba45ff4effe73c414266510109e701
@@ -1550,7 +1550,7 @@ F test/notnull.test a37b663d5bb728d66fc182016613fb8e4a0a4bbf3d75b8876a7527f7d4ed
 F test/notnull2.test c2c7b670fb8fa6ffe5f9cc08af88864fbb8237e28b56ad528e8dee921019c5fe
 F test/notnullfault.test fc4bb7845582a2b3db376001ef49118393b1b11abe0d24adb03db057ee2b73d5
 F test/null.test b7ff206a1c60fe01aa2abd33ef9ea83c93727d993ca8a613de86e925c9f2bc6f
-F test/nulls1.test b21d95f5a9b688b147478429293606d558bb29fce4dcfa983da2b098aec3a896
+F test/nulls1.test 0cd06a7f65c7c07c618388cc0c8bd58ce57c4ffe2efc7caea142059ac643038f
 F test/nulls2.test 20356ab1de69f78363faed9c2cd8eb455bb92f805572c405131f1c5d8f2d37fb
 F test/numcast.test 5d126f7f581432e86a90d1e35cac625164aec4a1
 F test/numindex1.test 20a5450d4b056e48cd5db30e659f13347a099823
@@ -2290,8 +2290,8 @@ F tool/warnings-clang.sh bbf6a1e685e534c92ec2bfba5b1745f34fb6f0bc2a362850723a9ee
 F tool/warnings.sh a554d13f6e5cf3760f041b87939e3d616ec6961859c3245e8ef701d1eafc2ca2
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
 F tool/winmain.c 00c8fb88e365c9017db14c73d3c78af62194d9644feaf60e220ab0f411f3604c
-P 59dec753df9eef252776b7d9937db43b0e0843c9791d6dcccda2ed4dad31ee2b
-R 29b9e4e76e87ed1efcb12d7ad5baff40
-U drh
-Z 49f61fff5011f3c17c09cc47fcf95917
+P 178677e14188117aada456fb068f6c9c6acf577ff6ebb211303e9227dd874e8f
+R def06fd90fb03b9e01545d5f4099a38c
+U dan
+Z 101fc5457fc6eebfb086e5d63b91b5b8
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 19df94323d..a9f6da1578 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-178677e14188117aada456fb068f6c9c6acf577ff6ebb211303e9227dd874e8f
+a2a20c54a2ce7a43a253f496210e8ff39215cd18b17895b62ef963fe449f3ab2
diff --git a/src/where.c b/src/where.c
index 32581855bb..f67ed20c65 100644
--- a/src/where.c
+++ b/src/where.c
@@ -5457,7 +5457,14 @@ static i8 wherePathSatisfiesOrderBy(
           }
         }
         if( isMatch && (pOrderBy->a[i].fg.sortFlags & KEYINFO_ORDER_BIGNULL) ){
-          if( j==pLoop->u.btree.nEq ){
+          if( j==pLoop->u.btree.nEq 
+           && (HasRowid(pIndex->pTable)||!IsPrimaryKeyIndex(pIndex)||j<nKeyCol)
+          ){
+            /* If this is the PK of a WITHOUT ROWID table, do not use any
+            ** field past nKeyCol for a NULLS LAST sort. If ALTER TABLE has
+            ** been used to add columns to the table, this field may not
+            ** be present in all records, which causes problems for the seeks
+            ** used by NULLS LAST sorts.  */
             pLoop->wsFlags |= WHERE_BIGNULL_SORT;
           }else{
             isMatch = 0;
diff --git a/test/nulls1.test b/test/nulls1.test
index 11c31065f1..2878ed3893 100644
--- a/test/nulls1.test
+++ b/test/nulls1.test
@@ -416,6 +416,36 @@ do_execsql_test 12.9 {
   SELECT DISTINCT c0 FROM t0 INDEXED BY i0 ORDER BY c0 ASC NULLS LAST;
 } {A {}}
 
+#-------------------------------------------------------------------------
+# Report <https://sqlite.org/bugs/forumpost/d459ae35bd>
+#
+reset_db
+
+do_execsql_test 13.0 {
+  CREATE TABLE t1(a PRIMARY KEY) WITHOUT ROWID;
+  INSERT INTO t1 VALUES(1.5);
+  ALTER TABLE t1 ADD COLUMN b;
+  PRAGMA integrity_check;
+} {ok}
+
+do_execsql_test 13.1 {
+  SELECT * FROM t1 WHERE a IN (1.5, 'myval2') ORDER BY b NULLS LAST;
+} {1.5 {}}
+
+do_execsql_test 13.2 {
+  SELECT * FROM t1 WHERE a = 1.5 AND b IS NULL;
+} {1.5 {}}
+
+do_execsql_test 13.3 {
+  CREATE TABLE t2(a PRIMARY KEY) WITHOUT ROWID;
+  INSERT INTO t2 VALUES(1), (2);
+  ALTER TABLE t2 ADD COLUMN b DEFAULT 5;
+  INSERT INTO t2 VALUES(3, NULL);
+}
+
+do_execsql_test 13.4 {
+  SELECT * FROM t2 WHERE a IN (1, 2, 3) ORDER BY b NULLS LAST;
+} {1 5 2 5 3 {}}
 
 
 finish_test