python3-pyjwt: Fix CVE-2026-48522

Restrict PyJWKClient JWKS retrieval to HTTP and HTTPS. urllib
otherwise accepts schemes such as file, FTP and data, allowing
attacker-influenced URLs to reach unintended resources.

This patch applies the relevant subset of the upstream 2.13.0 fix.
The upstream commit is referenced in [1], and the public advisory is
referenced in [2].

[1] https://github.com/jpadilla/pyjwt/commit/95791b1759b8aa4f2203575d344d5c78564cdc81
[2] https://github.com/advisories/GHSA-993g-76c3-p5m4

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>
This commit is contained in:
Hetvi Thakar
2026-08-05 22:50:57 -07:00
committed by Anuj Mittal
parent 49bb7f1369
commit 773e345eca
2 changed files with 98 additions and 1 deletions
@@ -0,0 +1,94 @@
From ff542029d6865add176b3d4b650d8f1dc514ac85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@users.noreply.github.com>
Date: Mon, 3 Aug 2026 03:20:44 -0700
Subject: [PATCH] PyJWKClient: reject non-HTTP(S) JWKS URIs
Restrict JWKS retrieval to HTTP and HTTPS. urllib otherwise accepts
additional schemes such as file, FTP and data, allowing
attacker-influenced URLs to reach unintended resources.
CVE: CVE-2026-48522
Upstream-Status: Backport [https://github.com/jpadilla/pyjwt/commit/95791b1759b8aa4f2203575d344d5c78564cdc81]
Backport Changes:
- Extracted only the CVE-2026-48522 URI-scheme validation and regression
tests from the bundled upstream 2.13.0 commit. The other requested CVE
fixes are carried as separate patches.
- Adapted the hunk context to the PyJWT 2.8.0 constructor and typing imports.
- Omitted upstream test comments while retaining the same URI cases and
assertions.
- Omitted the 2.13.0 version and changelog updates, CVE-2026-48523 (which
does not affect 2.8.0), and unrelated hardening from the bundled commit.
(cherry picked from commit 95791b1759b8aa4f2203575d344d5c78564cdc81)
Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
---
jwt/jwks_client.py | 11 +++++++++++
tests/test_jwks_client.py | 25 +++++++++++++++++++++++++
2 files changed, 36 insertions(+)
diff --git a/jwt/jwks_client.py b/jwt/jwks_client.py
index f19b10a..18de342 100644
--- a/jwt/jwks_client.py
+++ b/jwt/jwks_client.py
@@ -4,6 +4,7 @@ from functools import lru_cache
from ssl import SSLContext
from typing import Any, Dict, List, Optional
from urllib.error import URLError
+from urllib.parse import urlparse
from .api_jwk import PyJWK, PyJWKSet
from .api_jwt import decode_complete as decode_token
@@ -25,6 +26,16 @@ class PyJWKClient:
):
if headers is None:
headers = {}
+ # urllib's default OpenerDirector also handles file://, ftp://, and
+ # data: URIs. Reject anything that isn't http(s) eagerly so a caller
+ # passing an attacker-influenced URL (e.g. taken from a `jku` token
+ # header) can't read local files or reach other unintended schemes.
+ scheme = urlparse(uri).scheme.lower()
+ if scheme not in ("http", "https"):
+ raise PyJWKClientError(
+ f"Invalid JWKS URI scheme {scheme!r}: only 'http' and 'https' "
+ f"are supported."
+ )
self.uri = uri
self.jwk_set_cache: Optional[JWKSetCache] = None
self.headers = headers
diff --git a/tests/test_jwks_client.py b/tests/test_jwks_client.py
index c3951ea..d4bdd35 100644
--- a/tests/test_jwks_client.py
+++ b/tests/test_jwks_client.py
@@ -327,6 +327,31 @@ class TestPyJWKClient:
jwks_client = PyJWKClient(url, lifespan=-1)
assert jwks_client is None
+ @pytest.mark.parametrize(
+ "uri",
+ [
+ "file:///etc/passwd",
+ "ftp://example.org/keys.json",
+ 'data:application/json,{"keys":[]}',
+ "/etc/passwd",
+ "ldap://internal.test/jwks",
+ ],
+ )
+ def test_pyjwkclient_rejects_non_http_schemes(self, uri: str) -> None:
+ with pytest.raises(PyJWKClientError, match="Invalid JWKS URI scheme"):
+ PyJWKClient(uri)
+
+ @pytest.mark.parametrize(
+ "uri",
+ [
+ "http://localhost/jwks.json",
+ "https://example.test/jwks.json",
+ "HTTPS://Example.Test/jwks.json",
+ ],
+ )
+ def test_pyjwkclient_accepts_http_https_schemes(self, uri: str) -> None:
+ PyJWKClient(uri)
+
def test_get_jwt_set_timeout(self):
url = "https://dev-87evx9ru.auth0.com/.well-known/jwks.json"
jwks_client = PyJWKClient(url, timeout=5)
@@ -5,7 +5,10 @@ HOMEPAGE = "http://github.com/jpadilla/pyjwt"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://LICENSE;md5=e4b56d2c9973d8cf54655555be06e551"
SRC_URI += "file://CVE-2026-32597.patch"
SRC_URI += " \
file://CVE-2026-32597.patch \
file://CVE-2026-48522.patch \
"
SRC_URI[sha256sum] = "57e28d156e3d5c10088e0c68abb90bfac3df82b40a71bd0daa20c65ccd5c23de"
PYPI_PACKAGE = "PyJWT"