new file mode 100644
@@ -0,0 +1,295 @@
+From 9fff50c82e4fd6baa8252cb573d4a5f3df1a9dcb Mon Sep 17 00:00:00 2001
+From: "J. Nick Koston" <nick@koston.org>
+Date: Sun, 7 Jun 2026 00:40:24 -0500
+Subject: [PATCH] [PR #12824/60b85e98 backport][3.14] Preserve host-only cookie
+ scope across CookieJar save/load (#12833)
+
+CVE: CVE-2026-54279
+Upstream-Status: Backport [https://github.com/aio-libs/aiohttp/commit/a329a7aacad5284f087af36103aff778746da0f2]
+
+(cherry picked from commit a329a7aacad5284f087af36103aff778746da0f2)
+Signed-off-by: Darsh Kelaiya <dkelaiya@cisco.com>
+---
+ CHANGES/12824.bugfix.rst | 1 +
+ aiohttp/cookiejar.py | 52 ++++++++++-----
+ tests/test_cookiejar.py | 135 +++++++++++++++++++++++++++++++++++++++
+ 3 files changed, 171 insertions(+), 17 deletions(-)
+ create mode 100644 CHANGES/12824.bugfix.rst
+
+diff --git a/CHANGES/12824.bugfix.rst b/CHANGES/12824.bugfix.rst
+new file mode 100644
+index 000000000..f8dbd169c
+--- /dev/null
++++ b/CHANGES/12824.bugfix.rst
+@@ -0,0 +1 @@
++Fixed :class:`~aiohttp.CookieJar` dropping the host-only flag of cookies when persisted with :meth:`~aiohttp.CookieJar.save` and reloaded with :meth:`~aiohttp.CookieJar.load`, so a cookie set without a ``Domain`` attribute is again scoped to the exact host that set it after a reload; the absolute expiration deadline is now persisted as well, so a reloaded cookie keeps its original lifetime instead of being rescheduled from the load time. :meth:`~aiohttp.CookieJar.load` now replaces the jar contents rather than merging onto prior state, and loaded cookies pass through the same acceptance rules as :meth:`~aiohttp.CookieJar.update_cookies`, so a cookie for an IP-address host is dropped when loaded into a jar created without ``unsafe=True`` -- by :user:`bdraco`.
+diff --git a/aiohttp/cookiejar.py b/aiohttp/cookiejar.py
+index 757cc10e8..b07d1fd50 100644
+--- a/aiohttp/cookiejar.py
++++ b/aiohttp/cookiejar.py
+@@ -48,6 +48,9 @@ _FORMAT_DOMAIN_REVERSED = "{1}.{0}".format
+ _MIN_SCHEDULED_COOKIE_EXPIRATION = 100
+ _SIMPLE_COOKIE = SimpleCookie()
+
++# Not persisted; the absolute deadline is saved instead.
++_RELATIVE_EXPIRY_ATTRS = frozenset(("max-age", "expires"))
++
+
+ class _RestrictedCookieUnpickler(pickle.Unpickler):
+ """A restricted unpickler that only allows cookie-related types.
+@@ -165,21 +168,28 @@ class CookieJar(AbstractCookieJar):
+ :class:`str` or :class:`pathlib.Path` instance.
+ """
+ file_path = pathlib.Path(file_path)
+- data: dict[str, dict[str, dict[str, str | bool]]] = {}
++ data: dict[str, dict[str, dict[str, str | bool | float]]] = {}
+ for (domain, path), cookie in self._cookies.items():
+ key = f"{domain}|{path}"
+ data[key] = {}
+ for name, morsel in cookie.items():
+- morsel_data: dict[str, str | bool] = {
++ morsel_data: dict[str, str | bool | float] = {
+ "key": morsel.key,
+ "value": morsel.value,
+ "coded_value": morsel.coded_value,
+ }
+- # Save all morsel attributes that have values
++ # Skip relative expiry; the absolute deadline is saved below.
+ for attr in morsel._reserved: # type: ignore[attr-defined]
++ if attr in _RELATIVE_EXPIRY_ATTRS:
++ continue
+ attr_val = morsel[attr]
+ if attr_val:
+ morsel_data[attr] = attr_val
++ # Persist or it reloads as a domain cookie and leaks to subdomains.
++ if (domain, name) in self._host_only_cookies:
++ morsel_data["host_only"] = True
++ if (exp := self._expirations.get((domain, path, name))) is not None:
++ morsel_data["expires_timestamp"] = exp
+ data[key][name] = morsel_data
+ with file_path.open(mode="w", encoding="utf-8") as f:
+ json.dump(data, f, indent=2)
+@@ -191,6 +201,9 @@ class CookieJar(AbstractCookieJar):
+ pickle format (using a restricted unpickler) for backward
+ compatibility with existing cookie files.
+
++ Replaces the current jar contents; loaded cookies pass through the
++ same acceptance rules as :meth:`update_cookies`.
++
+ :param file_path: Path to file from where cookies will be
+ imported, :class:`str` or :class:`pathlib.Path` instance.
+ """
+@@ -199,32 +212,28 @@ class CookieJar(AbstractCookieJar):
+ try:
+ with file_path.open(mode="r", encoding="utf-8") as f:
+ data = json.load(f)
+- self._cookies = self._load_json_data(data)
++ self._load_json_data(data)
+ except (json.JSONDecodeError, UnicodeDecodeError, ValueError):
+ # Fall back to legacy pickle format with restricted unpickler
+ with file_path.open(mode="rb") as f:
+ self._cookies = _RestrictedCookieUnpickler(f).load()
+
+ def _load_json_data(
+- self, data: dict[str, dict[str, dict[str, str | bool]]]
+- ) -> defaultdict[tuple[str, str], SimpleCookie]:
+- """Load cookies from parsed JSON data."""
+- cookies: defaultdict[tuple[str, str], SimpleCookie] = defaultdict(SimpleCookie)
++ self, data: dict[str, dict[str, dict[str, str | bool | float]]]
++ ) -> None:
++ """Replace contents, routing cookies through update_cookies()."""
++ self.clear()
+ for compound_key, cookie_data in data.items():
+ domain, path = compound_key.split("|", 1)
+- key = (domain, path)
+ for name, morsel_data in cookie_data.items():
+ morsel: Morsel[str] = Morsel()
+- morsel_key = morsel_data["key"]
+- morsel_value = morsel_data["value"]
+- morsel_coded_value = morsel_data["coded_value"]
+ # Use __setstate__ to bypass validation, same pattern
+ # used in _build_morsel and _cookie_helpers.
+ morsel.__setstate__( # type: ignore[attr-defined]
+ {
+- "key": morsel_key,
+- "value": morsel_value,
+- "coded_value": morsel_coded_value,
++ "key": morsel_data["key"],
++ "value": morsel_data["value"],
++ "coded_value": morsel_data["coded_value"],
+ }
+ )
+ # Restore morsel attributes
+@@ -235,8 +244,17 @@ class CookieJar(AbstractCookieJar):
+ "coded_value",
+ ):
+ morsel[attr] = morsel_data[attr]
+- cookies[key][name] = morsel
+- return cookies
++ # Drop the domain so update_cookies() re-marks it host-only.
++ if morsel_data.get("host_only"):
++ morsel["domain"] = ""
++ response_url = (
++ URL.build(scheme="https", host=domain) if domain else URL()
++ )
++ self.update_cookies({name: morsel}, response_url)
++ # Restore the absolute deadline; update_cookies() schedules none.
++ if (exp := morsel_data.get("expires_timestamp")) is not None:
++ self._expire_cookie(float(exp), domain, path, name)
++ self._do_expiration()
+
+ def clear(self, predicate: Optional[ClearCookiePredicate] = None) -> None:
+ if predicate is None:
+diff --git a/tests/test_cookiejar.py b/tests/test_cookiejar.py
+index 694514067..ba7ee3220 100644
+--- a/tests/test_cookiejar.py
++++ b/tests/test_cookiejar.py
+@@ -2,6 +2,7 @@ import asyncio
+ import datetime
+ import heapq
+ import itertools
++import json
+ import logging
+ import pathlib
+ import pickle
+@@ -1760,6 +1761,140 @@ async def test_save_load_json_partitioned_cookies(tmp_path: Path) -> None:
+ assert s["path"] == lo["path"]
+
+
++async def test_save_load_json_preserves_host_only_scope(tmp_path: Path) -> None:
++ """Verify save/load keeps host-only cookies off subdomains."""
++ file_path = tmp_path / "host_only.json"
++ issuer = URL("https://auth.example.com/login")
++ subdomain = URL("https://sub.auth.example.com/")
++
++ jar_save = CookieJar()
++ jar_save.update_cookies({"sid": "hostonly"}, response_url=issuer)
++ assert "sid" not in jar_save.filter_cookies(subdomain)
++ jar_save.save(file_path=file_path)
++
++ jar_load = CookieJar()
++ jar_load.load(file_path=file_path)
++
++ assert jar_load.host_only_cookies == frozenset({("auth.example.com", "sid")})
++ assert "sid" not in jar_load.filter_cookies(subdomain)
++ assert "sid" in jar_load.filter_cookies(issuer)
++
++
++async def test_save_load_json_domain_cookie_still_matches_subdomain(
++ tmp_path: Path,
++) -> None:
++ """Verify save/load keeps an explicit Domain cookie valid for subdomains."""
++ file_path = tmp_path / "domain.json"
++ subdomain = URL("https://sub.example.com/")
++
++ jar_save = CookieJar()
++ jar_save.update_cookies_from_headers(
++ ["sid=domaincookie; Domain=example.com"], URL("https://example.com/")
++ )
++ jar_save.save(file_path=file_path)
++
++ jar_load = CookieJar()
++ jar_load.load(file_path=file_path)
++
++ assert jar_load.host_only_cookies == frozenset()
++ assert "sid" in jar_load.filter_cookies(subdomain)
++
++
++async def test_save_load_json_preserves_max_age_deadline(tmp_path: Path) -> None:
++ """Verify save/load restores the absolute deadline without resetting it."""
++ file_path = tmp_path / "max_age.json"
++ url = URL("https://example.com/")
++
++ jar_save = CookieJar()
++ jar_save.update_cookies_from_headers(
++ ["sid=x; Max-Age=3600; Domain=example.com"], url
++ )
++ expirations = dict(jar_save._expirations)
++ jar_save.save(file_path=file_path)
++
++ jar_load = CookieJar()
++ jar_load.load(file_path=file_path)
++
++ # The deadline is restored as the original absolute time, not now + Max-Age.
++ assert dict(jar_load._expirations) == expirations
++ assert "sid" in jar_load.filter_cookies(url)
++
++
++async def test_save_load_json_drops_expired_cookie(tmp_path: Path) -> None:
++ """Verify a cookie whose persisted deadline is in the past is dropped on load."""
++ file_path = tmp_path / "expired.json"
++ url = URL("https://example.com/")
++
++ # Save a future-expiring cookie, then rewrite its persisted deadline to the
++ # past so the cookie survives save() and the drop happens on the load path.
++ jar_save = CookieJar()
++ jar_save.update_cookies_from_headers(
++ ["sid=x; Expires=Tue, 1 Jan 2999 12:00:00 GMT; Domain=example.com"], url
++ )
++ jar_save.save(file_path=file_path)
++ data = json.loads(file_path.read_text())
++ _, cookies = next(iter(data.items()))
++ cookies["sid"]["expires_timestamp"] = 0.0
++ file_path.write_text(json.dumps(data))
++
++ jar_load = CookieJar()
++ jar_load.load(file_path=file_path)
++
++ assert len(jar_load) == 0
++ assert "sid" not in jar_load.filter_cookies(url)
++
++
++async def test_save_load_json_preserves_expires_deadline(tmp_path: Path) -> None:
++ """Verify a future Expires deadline survives a save/load roundtrip."""
++ file_path = tmp_path / "expires.json"
++ url = URL("https://example.com/")
++
++ jar_save = CookieJar()
++ jar_save.update_cookies_from_headers(
++ ["sid=x; Expires=Tue, 1 Jan 2999 12:00:00 GMT; Domain=example.com"], url
++ )
++ expirations = dict(jar_save._expirations)
++ jar_save.save(file_path=file_path)
++
++ jar_load = CookieJar()
++ jar_load.load(file_path=file_path)
++
++ assert dict(jar_load._expirations) == expirations
++ assert "sid" in jar_load.filter_cookies(url)
++
++
++async def test_load_json_old_format_without_new_keys(tmp_path: Path) -> None:
++ """Verify a file written by an older version (no host_only/expires_timestamp) loads."""
++ file_path = tmp_path / "old.json"
++ # Old schema: no host_only, no expires_timestamp; relative max-age morsel attr.
++ file_path.write_text(
++ json.dumps(
++ {
++ "example.com|/": {
++ "sid": {
++ "key": "sid",
++ "value": "x",
++ "coded_value": "x",
++ "domain": "example.com",
++ "max-age": "3600",
++ }
++ }
++ }
++ )
++ )
++ url = URL("https://example.com/")
++
++ jar_load = CookieJar()
++ # No exception when the new keys are absent.
++ jar_load.load(file_path=file_path)
++
++ # A host-only cookie saved without Domain by an older version had no domain
++ # field, so it now loads as a domain cookie (the documented migration loss).
++ assert "sid" in jar_load.filter_cookies(url)
++ # max-age is rescheduled from load time rather than an absolute deadline.
++ assert any(key[2] == "sid" for key in jar_load._expirations)
++
++
+ async def test_json_format_is_safe(tmp_path: Path) -> None:
+ """Verify the JSON file format cannot execute code on load."""
+ import json
@@ -15,6 +15,7 @@ SRC_URI += " \
file://CVE-2026-54276.patch \
file://CVE-2026-54277.patch \
file://CVE-2026-54278.patch \
+ file://CVE-2026-54279.patch \
"
CVE_PRODUCT = "aiohttp"