diff mbox series

[meta-python,wrynose,2/6] python3-pyjwt: Fix CVE-2026-48523

Message ID 20260819110016.252278-2-hthakar@cisco.com
State New
Headers show
Series [meta-python,wrynose,1/6] python3-pyjwt: Fix CVE-2026-48522 | expand

Commit Message

From: Hetvi Thakar <hthakar@cisco.com>

This patch applies the upstream 2.13.0 backport for
CVE-2026-48523. The upstream fix commit is referenced in [1],
and the public CVE advisory is referenced in [2].

[1] https://github.com/jpadilla/pyjwt/commit/95791b1759b8aa4f2203575d344d5c78564cdc81
[2] https://github.com/advisories/GHSA-jq35-7prp-9v3f

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
---
 .../python/files/CVE-2026-48523.patch         | 115 ++++++++++++++++++
 .../python/python3-pyjwt_2.12.1.bb            |   4 +-
 2 files changed, 118 insertions(+), 1 deletion(-)
 create mode 100644 meta-python/recipes-devtools/python/files/CVE-2026-48523.patch
diff mbox series

Patch

diff --git a/meta-python/recipes-devtools/python/files/CVE-2026-48523.patch b/meta-python/recipes-devtools/python/files/CVE-2026-48523.patch
new file mode 100644
index 0000000000..f272338979
--- /dev/null
+++ b/meta-python/recipes-devtools/python/files/CVE-2026-48523.patch
@@ -0,0 +1,115 @@ 
+From 6590add3a8d18098b107fe446ff256ae92e7238f Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@users.noreply.github.com>
+Date: Thu, 21 May 2026 14:11:10 -0400
+Subject: [PATCH] Bundle security fixes and hardening into 2.13.0
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Security:
+- `HMACAlgorithm.prepare_key` rejects JWK JSON documents passed as raw
+  HMAC secrets to close an algorithm-confusion gap not covered by the
+  existing PEM/SSH guard. Reported by @aradona91 in GHSA-xgmm-8j9v-c9wx.
+- Bind the JWT header `alg` to `PyJWK.algorithm_name` during verification
+  so the caller's `algorithms` allow-list cannot be bypassed when decoding
+  with a `PyJWK` / `PyJWKClient` key. Reported by @sushi-gif in
+  GHSA-jq35-7prp-9v3f.
+- Skip the unconditional base64 decode of the compact-form payload
+  segment when `b64=false` is set, and require that segment to be empty
+  (RFC 7515 Appendix F detached form). Closes an unauthenticated DoS
+  amplifier. Reported by @thesmartshadow in GHSA-w7vc-732c-9m39.
+- `PyJWKClient` rejects any URI whose scheme is not `http` or `https` so
+  attacker-influenced URIs cannot read local files or reach unintended
+  schemes via urllib's default `file://` / `ftp://` / `data:` handlers.
+  Reported by @KEIJOT in GHSA-993g-76c3-p5m4.
+- Preserve the cached JWK Set on fetch errors in `PyJWKClient.fetch_data`.
+  The previous `finally`-block `put(None)` pattern cleared the cache on
+  any transient outage. Reported by @eddieran in GHSA-fhv5-28vv-h8m8.
+
+Fixes:
+- Reject empty HMAC keys outright in `HMACAlgorithm.prepare_key` with
+  `InvalidKeyError` instead of accepting them with only a warning.
+  Hardening prompted by reports from @SnailSploit and @spartan8806.
+- Forward per-call `options` (including `enforce_minimum_key_length`)
+  from `PyJWT.decode` through to `PyJWS._verify_signature`. Thanks to
+  @WLUB.
+- RFC 7797 §3 compliance for `b64=false`: encoder auto-adds `"b64"` to
+  `crit`; decoder rejects tokens that set `b64=false` without listing
+  it in `crit`. Thanks to @MachineLearning-Nerd.
+
+CVE: CVE-2026-48523
+Upstream-Status: Backport [https://github.com/jpadilla/pyjwt/commit/95791b1759b8aa4f2203575d344d5c78564cdc81]
+
+Backport Changes:
+- Split out the PyJWK algorithm-binding validation because the upstream
+  commit bundles multiple CVEs.
+- Omitted CHANGELOG.rst because it conflicted and is release documentation.
+- Omitted the 2.13.0 version bump and other bundled fixes; applicable CVE
+  fixes are carried in separate patches.
+
+(cherry picked from commit 95791b1759b8aa4f2203575d344d5c78564cdc81)
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ jwt/api_jws.py        | 10 ++++++++++
+ tests/test_api_jws.py | 27 +++++++++++++++++++++++++++
+ 2 files changed, 37 insertions(+)
+
+diff --git a/jwt/api_jws.py b/jwt/api_jws.py
+index 0ab7e4b..91d2ae3 100644
+--- a/jwt/api_jws.py
++++ b/jwt/api_jws.py
+@@ -348,6 +348,16 @@ class PyJWS:
+             raise InvalidAlgorithmError("The specified alg value is not allowed")
+ 
+         if isinstance(key, PyJWK):
++            # The PyJWK has a fixed algorithm bound at construction time.
++            # Verification must use that algorithm, not whatever the token
++            # header advertises, otherwise the caller's allow-list check
++            # above degenerates into a string compare with no behavioural
++            # effect on which algorithm actually verifies the signature.
++            if alg != key.algorithm_name:
++                raise InvalidAlgorithmError(
++                    f"Token algorithm {alg!r} does not match the key's "
++                    f"algorithm {key.algorithm_name!r}"
++                )
+             alg_obj = key.Algorithm
+             prepared_key = key.key
+         else:
+diff --git a/tests/test_api_jws.py b/tests/test_api_jws.py
+index 9f7edc0..0715b9e 100644
+--- a/tests/test_api_jws.py
++++ b/tests/test_api_jws.py
+@@ -397,6 +397,33 @@ class TestJWS:
+         with pytest.raises(InvalidAlgorithmError):
+             jws.decode(example_jws, jwk)
+ 
++    def test_decodes_with_jwk_rejects_header_alg_outside_jwk_alg(
++        self, jws: PyJWS
++    ) -> None:
++        # Token header says HS256 and the caller's allow-list also accepts
++        # HS256, but the PyJWK is bound to HS512. Even though the allow-list
++        # would pass, verification must be locked to the PyJWK's algorithm
++        # rather than the header's — otherwise an attacker who controls a
++        # registered key can advertise a disallowed algorithm in the header
++        # and have it accepted.
++        jwk = PyJWK(
++            {
++                "kty": "oct",
++                "alg": "HS512",
++                "k": "c2VjcmV0",  # "secret"
++            }
++        )
++        example_jws = (
++            b"eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9."
++            b"aGVsbG8gd29ybGQ."
++            b"gEW0pdU4kxPthjtehYdhxB9mMOGajt1xCKlGGXDJ8PM"
++        )
++
++        with pytest.raises(
++            InvalidAlgorithmError, match="does not match the key's algorithm"
++        ):
++            jws.decode(example_jws, jwk, algorithms=["HS256", "HS512"])
++
+     # 'Control' Elliptic Curve jws created by another library.
+     # Used to test for regressions that could affect both
+     # encoding / decoding operations equally (causing tests
diff --git a/meta-python/recipes-devtools/python/python3-pyjwt_2.12.1.bb b/meta-python/recipes-devtools/python/python3-pyjwt_2.12.1.bb
index ed7a280ee5..e67c7bae2f 100644
--- a/meta-python/recipes-devtools/python/python3-pyjwt_2.12.1.bb
+++ b/meta-python/recipes-devtools/python/python3-pyjwt_2.12.1.bb
@@ -5,7 +5,9 @@  HOMEPAGE = "https://github.com/jpadilla/pyjwt"
 LICENSE = "MIT"
 LIC_FILES_CHKSUM = "file://LICENSE;md5=e4b56d2c9973d8cf54655555be06e551"
 
-SRC_URI += "file://CVE-2026-48522.patch"
+SRC_URI += "file://CVE-2026-48522.patch \
+           file://CVE-2026-48523.patch \
+           "
 
 SRC_URI[sha256sum] = "c74a7a2adf861c04d002db713dd85f84beb242228e671280bf709d765b03672b"