new file mode 100644
@@ -0,0 +1,96 @@
+From 83788a36c646a1bdfba912267feab5db796a828e Mon Sep 17 00:00:00 2001
+From: "J. Nick Koston" <nick@koston.org>
+Date: Sun, 7 Jun 2026 00:33:03 -0500
+Subject: [PATCH] [PR #12826/36df6c13 backport][3.14] Enforce max_line_size on
+ fragmented request target and reason in C parser (#12837)
+
+CVE: CVE-2026-54277
+Upstream-Status: Backport [https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d]
+
+Backport Changes:
+- Omitted generated `aiohttp/_http_parser.c` changes because the
+ Scarthgap recipe regenerates that file from `_http_parser.pyx`
+ during `do_configure`.
+- This fix depends on the max_line_size buffer logic introduced by
+ CVE-2026-22815. Keep CVE-2026-22815.patch earlier in SRC_URI.
+
+(cherry picked from commit 5ab61bb4cd88f19b712f12c7c9295fe262bf804d)
+Signed-off-by: Darsh Kelaiya <dkelaiya@cisco.com>
+---
+ CHANGES/12826.bugfix.rst | 1 +
+ aiohttp/_http_parser.pyx | 4 ++--
+ tests/test_http_parser.py | 22 ++++++++++++++++++++++
+ 3 files changed, 25 insertions(+), 2 deletions(-)
+ create mode 100644 CHANGES/12826.bugfix.rst
+
+diff --git a/CHANGES/12826.bugfix.rst b/CHANGES/12826.bugfix.rst
+new file mode 100644
+index 000000000..7e095615d
+--- /dev/null
++++ b/CHANGES/12826.bugfix.rst
+@@ -0,0 +1 @@
++Fixed the C HTTP parser not enforcing ``max_line_size`` on a request target or response reason phrase that is split across multiple reads; each fragment was checked on its own, so an accumulated line could exceed the limit without raising ``LineTooLong``. The accumulated length is now checked, matching the pure-Python parser -- by :user:`bdraco`.
+diff --git a/aiohttp/_http_parser.pyx b/aiohttp/_http_parser.pyx
+index 8e9ecae69..01a0f859c 100644
+--- a/aiohttp/_http_parser.pyx
++++ b/aiohttp/_http_parser.pyx
+@@ -718,7 +718,7 @@ cdef int cb_on_url(cparser.llhttp_t* parser,
+ const char *at, size_t length) except -1:
+ cdef HttpParser pyparser = <HttpParser>parser.data
+ try:
+- if length > pyparser._max_line_size:
++ if len(pyparser._buf) + length > pyparser._max_line_size:
+ status = pyparser._buf + at[:length]
+ raise LineTooLong(status[:100] + b"...", pyparser._max_line_size)
+ extend(pyparser._buf, at, length)
+@@ -733,7 +733,7 @@ cdef int cb_on_status(cparser.llhttp_t* parser,
+ const char *at, size_t length) except -1:
+ cdef HttpParser pyparser = <HttpParser>parser.data
+ try:
+- if length > pyparser._max_line_size:
++ if len(pyparser._buf) + length > pyparser._max_line_size:
+ reason = pyparser._buf + at[:length]
+ raise LineTooLong(reason[:100] + b"...", pyparser._max_line_size)
+ extend(pyparser._buf, at, length)
+diff --git a/tests/test_http_parser.py b/tests/test_http_parser.py
+index 3e1f7dfaa..a724aae63 100644
+--- a/tests/test_http_parser.py
++++ b/tests/test_http_parser.py
+@@ -1161,6 +1161,17 @@ def test_http_request_max_status_line_under_limit(parser: HttpRequestParser) ->
+ assert msg.url == URL("/path" + path.decode())
+
+
++def test_http_request_max_status_line_fragmented(
++ parser: HttpRequestParser,
++) -> None:
++ # Split an overlong request target across reads so that each callback
++ # fragment is under the limit but the accumulated target is not.
++ match = "400, message:\n Got more than 8190 bytes when reading"
++ with pytest.raises(http_exceptions.LineTooLong, match=match):
++ parser.feed_data(b"GET /" + b"a" * 8000)
++ parser.feed_data(b"a" * 8000 + b" HTTP/1.1\r\nHost: a\r\n\r\n")
++
++
+ def test_http_response_parser_utf8(response) -> None:
+ text = "HTTP/1.1 200 Ok\r\nx-test:ัะตัั\r\n\r\n".encode()
+
+@@ -1238,6 +1249,17 @@ def test_http_response_parser_status_line_under_limit(
+ assert msg.reason == reason.decode()
+
+
++def test_http_response_parser_status_line_too_long_fragmented(
++ response: HttpResponseParser,
++) -> None:
++ # Split an overlong reason phrase across reads so that each callback
++ # fragment is under the limit but the accumulated reason is not.
++ match = "400, message:\n Got more than 8190 bytes when reading"
++ with pytest.raises(http_exceptions.LineTooLong, match=match):
++ response.feed_data(b"HTTP/1.1 200 " + b"a" * 8000)
++ response.feed_data(b"a" * 8000 + b"\r\n\r\n")
++
++
+ def test_http_response_parser_bad_version(response) -> None:
+ with pytest.raises(http_exceptions.BadHttpMessage):
+ response.feed_data(b"HT/11 200 Ok\r\n\r\n")
+--
+2.35.6
@@ -31,6 +31,7 @@ SRC_URI += "file://CVE-2024-52304.patch \
file://CVE-2026-50269.patch \
file://CVE-2026-54274.patch \
file://CVE-2026-54275.patch \
+ file://CVE-2026-54277.patch \
"
CVE_STATUS[CVE-2026-34515] = "not-applicable-platform: Vulnerability only affects applications running on Windows"