diff --git a/CHANGES.md b/CHANGES.md
index e36bc460c..39b2b8a14 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -18,6 +18,8 @@ v3.0.4 - YYYY-MM-DD
   by an unknown CA.
 - Fixed PAM support in `ippeveprinter`.
 - Updated dateTime parsing in IPP files.
+- Fixed use of an uninitialized `struct tm` in `httpGetDateString` when
+  `gmtime_r` fails for an out-of-range time value.
 
 
 v3.0.3 - 2026-08-20
diff --git a/cups/http-support.c b/cups/http-support.c
index 604187bc5..c55570696 100644
--- a/cups/http-support.c
+++ b/cups/http-support.c
@@ -636,7 +636,11 @@ httpGetDateString(time_t t,		// I - Time in seconds
   struct tm	tdate;			// UNIX date/time data
 
 
-  gmtime_r(&t, &tdate);
+  if (!gmtime_r(&t, &tdate))
+  {
+    memset(&tdate, 0, sizeof(tdate));
+    tdate.tm_mday = 1;
+  }
 
   snprintf(s, slen, "%s, %02d %s %d %02d:%02d:%02d GMT", http_days[tdate.tm_wday], tdate.tm_mday, http_months[tdate.tm_mon], tdate.tm_year + 1900, tdate.tm_hour, tdate.tm_min, tdate.tm_sec);