diff --git a/libs/server/Resp/BasicCommands.cs b/libs/server/Resp/BasicCommands.cs
index 8b25229045b..f10f5131c7d 100644
--- a/libs/server/Resp/BasicCommands.cs
+++ b/libs/server/Resp/BasicCommands.cs
@@ -115,21 +115,38 @@ bool NetworkGETEX<TGarnetApi>(ref TGarnetApi storageApi)
                     if (parseState.Count < 3 || !parseState.TryGetLong(2, out var expireTime) || expireTime <= 0)
                         return AbortWithErrorMessage(CmdStrings.RESP_ERR_GENERIC_VALUE_IS_OUT_OF_RANGE);
 
+                    // The expiry a GETEX option implies must land within the representable range so
+                    // that (a) the conversion itself does not throw - TimeSpan.From* raises an
+                    // OverflowException and DateTimeOffset.FromUnixTime* an ArgumentOutOfRangeException,
+                    // neither a RespParsingException nor a GarnetException, so it would escape to the
+                    // session catch-all and dispose the connection - and (b) the absolute expiry
+                    // computed below as UtcNow.Ticks + tsExpiry.Ticks does not silently overflow the
+                    // long. Both are bounded by refusing any expiry beyond DateTimeOffset.MaxValue
+                    // (year 9999), reporting an error the way Redis does rather than crashing.
+                    var maxDeltaTicks = DateTimeOffset.MaxValue.Ticks - DateTimeOffset.UtcNow.Ticks;
                     switch (option)
                     {
                         case var _ when option.EqualsUpperCaseSpanIgnoringCase(CmdStrings.EX):
+                            if (expireTime > maxDeltaTicks / TimeSpan.TicksPerSecond)
+                                return AbortWithErrorMessage(CmdStrings.RESP_ERR_GENERIC_INVALIDEXP_IN_GETEX);
                             tsExpiry = TimeSpan.FromSeconds(expireTime);
                             break;
 
                         case var _ when option.EqualsUpperCaseSpanIgnoringCase(CmdStrings.PX):
+                            if (expireTime > maxDeltaTicks / TimeSpan.TicksPerMillisecond)
+                                return AbortWithErrorMessage(CmdStrings.RESP_ERR_GENERIC_INVALIDEXP_IN_GETEX);
                             tsExpiry = TimeSpan.FromMilliseconds(expireTime);
                             break;
 
                         case var _ when option.EqualsUpperCaseSpanIgnoringCase(CmdStrings.EXAT):
+                            if (expireTime > DateTimeOffset.MaxValue.ToUnixTimeSeconds())
+                                return AbortWithErrorMessage(CmdStrings.RESP_ERR_GENERIC_INVALIDEXP_IN_GETEX);
                             tsExpiry = DateTimeOffset.FromUnixTimeSeconds(expireTime) - DateTimeOffset.UtcNow;
                             break;
 
                         case var _ when option.EqualsUpperCaseSpanIgnoringCase(CmdStrings.PXAT):
+                            if (expireTime > DateTimeOffset.MaxValue.ToUnixTimeMilliseconds())
+                                return AbortWithErrorMessage(CmdStrings.RESP_ERR_GENERIC_INVALIDEXP_IN_GETEX);
                             tsExpiry = DateTimeOffset.FromUnixTimeMilliseconds(expireTime) - DateTimeOffset.UtcNow;
                             break;
 
diff --git a/libs/server/Resp/CmdStrings.cs b/libs/server/Resp/CmdStrings.cs
index c04278d1eb7..1ab34958ec3 100644
--- a/libs/server/Resp/CmdStrings.cs
+++ b/libs/server/Resp/CmdStrings.cs
@@ -221,6 +221,7 @@ static partial class CmdStrings
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_DISCARD_WO_MULTI => "ERR DISCARD without MULTI"u8;
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_WATCH_IN_MULTI => "ERR WATCH inside MULTI is not allowed"u8;
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_INVALIDEXP_IN_SET => "ERR invalid expire time in 'set' command"u8;
+        public static ReadOnlySpan<byte> RESP_ERR_GENERIC_INVALIDEXP_IN_GETEX => "ERR invalid expire time in 'getex' command"u8;
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_SYNTAX_ERROR => "ERR syntax error"u8;
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_NAN_INFINITY => "ERR value is NaN or Infinity"u8;
         public static ReadOnlySpan<byte> RESP_ERR_GENERIC_NAN_INFINITY_INCR => "ERR increment would produce NaN or Infinity"u8;
diff --git a/test/standalone/Garnet.test/RespTests.cs b/test/standalone/Garnet.test/RespTests.cs
index eb54dccdd25..0fa48eb9c60 100644
--- a/test/standalone/Garnet.test/RespTests.cs
+++ b/test/standalone/Garnet.test/RespTests.cs
@@ -4964,6 +4964,41 @@ public void GetExpiryWitInvalidOptions(string optionsInput)
             Assert.Throws<RedisServerException>(() => db.Execute("GETEX", [key, .. options]));
         }
 
+        /// <summary>
+        /// An out-of-range expiry must be answered by an error and nothing else, and must leave the
+        /// connection usable. Two failure modes are covered:
+        /// - A value large enough that the conversion throws (EX/PX overflow <see cref="TimeSpan"/>,
+        ///   EXAT/PXAT run <see cref="DateTimeOffset.FromUnixTimeSeconds"/> past its year-9999
+        ///   ceiling). That exception used to escape to the session catch-all and tear the
+        ///   connection down - the trailing PING is the tell, a disposed session never answers it.
+        /// - A value in the gap below that ceiling but past DateTimeOffset.MaxValue (the last two
+        ///   cases): the conversion did not throw, but UtcNow.Ticks + delta silently overflowed the
+        ///   long into a negative absolute expiry, so GETEX applied a garbage TTL and replied with
+        ///   the value instead of an error.
+        /// </summary>
+        [Test]
+        [TestCase("EX 99999999999999")]
+        [TestCase("PX 99999999999999999")]
+        [TestCase("EXAT 99999999999999")]
+        [TestCase("PXAT 99999999999999999")]
+        [TestCase("EX 900000000000")]
+        [TestCase("PX 900000000000000")]
+        public void GetExpiryOutOfRangeIsRejectedWithoutKillingSession(string optionAndValue)
+        {
+            using var lightClientRequest = TestUtils.CreateRequest();
+
+            var expectedResponse = "-ERR invalid expire time in 'getex' command\r\n+PONG\r\n";
+
+            lightClientRequest.SendCommand("SET keyA valueA");
+
+            var response = lightClientRequest.SendCommands($"GETEX keyA {optionAndValue}", "PING", 1, 1);
+            TestUtils.AssertEqualUpToExpectedLength(expectedResponse, response);
+
+            // The rejected expiry must not have been applied.
+            response = lightClientRequest.SendCommand("TTL keyA");
+            TestUtils.AssertEqualUpToExpectedLength(":-1\r\n", response);
+        }
+
         #endregion
 
         #region GETSET