diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8644aa3e..cc5a153e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,9 +26,9 @@ If you are upgrading from v0.11.x or v0.12.x, this version includes **breaking c
 - IMAP: Include `administer` permission in ACL responses.
 - IMAP: Add owner rights to ACL get responses.
 - IMAP: Do not auto-train Bayes when moving messages from Junk to Trash.
-- IMAP/ManageSieve: Increase maximum quoted argument size (fixes #2039).
-- CalDAV: Limit recurrence expansions in calendar reports.
-- WebDAV: Do not fix percent encoding on WebDAV FS (closes #2036).
+- IMAP/ManageSieve: Increase maximum quoted argument size (#2039).
+- CalDAV: Limit recurrence expansions in calendar reports ([CVE-2025-59045](https://github.com/stalwartlabs/stalwart/security/advisories/GHSA-xv4r-q6gr-6pfg)).
+- WebDAV: Do not fix percent encoding on WebDAV FS (#2036).
 
 ## [0.13.2] - 2025-07-28
 
diff --git a/crates/imap-proto/src/receiver.rs b/crates/imap-proto/src/receiver.rs
index e8632b78..4d543d40 100644
--- a/crates/imap-proto/src/receiver.rs
+++ b/crates/imap-proto/src/receiver.rs
@@ -4,11 +4,11 @@
  * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
  */
 
+use super::{ResponseCode, ResponseType};
+use compact_str::{CompactString, format_compact};
 use std::fmt::Display;
 
-use compact_str::{CompactString, format_compact};
-
-use super::{ResponseCode, ResponseType};
+const QUOTED_ARG_MAX_LEN: usize = 4096;
 
 #[derive(Debug, Clone)]
 pub enum Error {
@@ -277,7 +277,7 @@ impl<T: CommandParser> Receiver<T> {
                         if !escaped {
                             self.push_argument(true)?;
                             self.state = State::Argument { last_ch: b' ' };
-                        } else if self.buf.len() < 4096 {
+                        } else if self.buf.len() < QUOTED_ARG_MAX_LEN {
                             self.buf.push(ch);
                             self.state = State::ArgumentQuoted { escaped: false };
                         } else {
@@ -286,7 +286,11 @@ impl<T: CommandParser> Receiver<T> {
                     }
                     b'\\' => {
                         if escaped {
-                            self.buf.push(ch);
+                            if self.buf.len() < QUOTED_ARG_MAX_LEN {
+                                self.buf.push(ch);
+                            } else {
+                                return Err(self.error_reset("Quoted argument too long."));
+                            }
                         }
                         self.state = State::ArgumentQuoted { escaped: !escaped };
                     }
@@ -294,7 +298,7 @@ impl<T: CommandParser> Receiver<T> {
                         return Err(self.error_reset("Unterminated quoted argument."));
                     }
                     _ => {
-                        if self.buf.len() < 4096 {
+                        if self.buf.len() < QUOTED_ARG_MAX_LEN {
                             if escaped {
                                 self.buf.push(b'\\');
                             }
@@ -340,7 +344,6 @@ impl<T: CommandParser> Receiver<T> {
                                 self.buf.push(ch);
                             } else {
                                 // Digit found after non-sync '+' flag
-
                                 return Err(self.error_reset("Invalid literal."));
                             }
                         }
diff --git a/tests/src/smtp/inbound/limits.rs b/tests/src/smtp/inbound/limits.rs
index 3d0f3e08..9012d4c6 100644
--- a/tests/src/smtp/inbound/limits.rs
+++ b/tests/src/smtp/inbound/limits.rs
@@ -40,7 +40,7 @@ async fn limits() {
     // Exceed max line length
     let mut session = Session::test_with_shutdown(TestSMTP::from_core(core).server, rx);
     session.data.remote_ip_str = "10.0.0.1".into();
-    let mut buf = vec![b'A'; 2049];
+    let mut buf = vec![b'A'; 4097];
     session.ingest(&buf).await.unwrap();
     session.ingest(b"\r\n").await.unwrap();
     session.response().assert_code("554 5.3.4");