[meta-python][wrynose][PATCH 4/6] python3-pyjwt: Fix CVE-2026-48525
"Hetvi Thakar -X (hthakar - E INFOCHIPS PRIVATE LIMITED at Cisco)" <[email protected]>
| Newsgroups | org.openembedded.lists.openembedded-devel |
|---|---|
| Message-ID | <[email protected]> |
From: Hetvi Thakar <[email protected]> This patch applies the upstream 2.13.0 backport for CVE-2026-48525. 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-w7vc-732c-9m39 Signed-off-by: Hetvi Thakar <[email protected]> --- .../python/files/CVE-2026-48525.patch | 146 ++++++++++++++++++ .../python/python3-pyjwt_2.12.1.bb | 1 + 2 files changed, 147 insertions(+) create mode 100644 meta-python/recipes-devtools/python/files/CVE-2026-48525.patch diff --git a/meta-python/recipes-devtools/python/files/CVE-2026-48525.patch b/meta-python/recipes-devtools/python/files/CVE-2026-48525.patch new file mode 100644 index 0000000000..9b7ffb97eb --- /dev/null +++ b/meta-python/recipes-devtools/python/files/CVE-2026-48525.patch @@ -0,0 +1,146 @@ +From e6152fb27dd439bf4541aab9b26a93134c48135f Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <[email protected]> +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-2026-48525 +Upstream-Status: Backport [https://github.com/jpadilla/pyjwt/commit/95791b1759b8aa4f2203575d344d5c78564cdc81] + +Backport Changes: +- Split out the b64=false payload-decoding DoS fix because the upstream + commit bundles multiple CVEs. +- Omitted CHANGELOG.rst because it conflicted and is release documentation. +- Carried the focused + `test_decode_b64_false_rejects_non_empty_payload_segment` regression test. + Omitted other tests/test_api_jws.py hunks for unrelated bundled fixes. +- 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 <[email protected]> +--- + jwt/api_jws.py | 22 ++++++++++++++++++---- + tests/test_api_jws.py | 36 +++++++++++++++++++++++++++++++++++- + 2 files changed, 53 insertions(+), 5 deletions(-) + +diff --git a/jwt/api_jws.py b/jwt/api_jws.py +index 91d2ae3..5a91bce 100644 +--- a/jwt/api_jws.py ++++ b/jwt/api_jws.py +@@ -317,10 +317,24 @@ class PyJWS: + if not isinstance(header, dict): + raise DecodeError("Invalid header string: must be a json object") + +- try: +- payload = base64url_decode(payload_segment) +- except (TypeError, binascii.Error) as err: +- raise DecodeError("Invalid payload padding") from err ++ if header.get("b64", True) is False: ++ # Detached payload form (RFC 7515 Appendix F): the compact-form ++ # payload segment must be empty; the caller supplies the actual ++ # payload via the `detached_payload` argument in decode_complete. ++ # Skipping the base64 decode here removes an unauthenticated work ++ # amplifier — otherwise an attacker can inflate the unused ++ # segment to force CPU + memory cost before the signature is ++ # even checked. ++ if payload_segment: ++ raise DecodeError( ++ "Payload segment must be empty when 'b64' is false." ++ ) ++ payload = b"" ++ else: ++ try: ++ payload = base64url_decode(payload_segment) ++ except (TypeError, binascii.Error) as err: ++ raise DecodeError("Invalid payload padding") from err + + try: + signature = base64url_decode(crypto_segment) +diff --git a/tests/test_api_jws.py b/tests/test_api_jws.py +index 0715b9e..01de813 100644 +--- a/tests/test_api_jws.py ++++ b/tests/test_api_jws.py +@@ -12,7 +12,7 @@ from jwt.exceptions import ( + InvalidSignatureError, + InvalidTokenError, + ) +-from jwt.utils import base64url_decode ++from jwt.utils import base64url_decode, base64url_encode + from jwt.warnings import RemovedInPyjwt3Warning + + from .utils import crypto_required, key_path, no_crypto_required +@@ -984,6 +984,40 @@ class TestJWS: + assert "b64" not in msg_header_obj + assert msg_payload + ++ def test_decode_b64_false_rejects_non_empty_payload_segment( ++ self, jws: PyJWS, payload: bytes ++ ) -> None: ++ # RFC 7515 Appendix F detached form: when b64=false, the compact- ++ # serialization payload segment must be empty. PyJWT must reject a ++ # non-empty middle segment without doing any base64-decoding work ++ # on it — that decode used to be the unauthenticated DoS amplifier. ++ secret = "secret" ++ import hmac as _hmac ++ import hashlib as _hashlib ++ ++ header_obj = { ++ "typ": "JWT", ++ "alg": "HS256", ++ "b64": False, ++ "crit": ["b64"], ++ } ++ header_b64 = base64url_encode( ++ json.dumps(header_obj, separators=(",", ":")).encode() ++ ) ++ # Stuff the middle segment with arbitrary attacker-controlled bytes. ++ # This should be rejected without being base64-decoded. ++ attacker_segment = b"A" * 1024 ++ signing_input = b".".join([header_b64, payload]) ++ sig = _hmac.new(secret.encode(), signing_input, _hashlib.sha256).digest() ++ token = b".".join( ++ [header_b64, attacker_segment, base64url_encode(sig)] ++ ).decode() ++ ++ with pytest.raises(DecodeError, match="Payload segment must be empty"): ++ jws.decode( ++ token, secret, algorithms=["HS256"], detached_payload=payload ++ ) ++ + def test_decode_detached_content_without_proper_argument(self, jws: PyJWS) -> None: + example_jws = ( + "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiIsImI2NCI6ZmFsc2V9" 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 ff3eb8814d..3e68f9c0b3 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 @@ -8,6 +8,7 @@ LIC_FILES_CHKSUM = "file://LICENSE;md5=e4b56d2c9973d8cf54655555be06e551" SRC_URI += "file://CVE-2026-48522.patch \ file://CVE-2026-48523.patch \ file://CVE-2026-48524.patch \ + file://CVE-2026-48525.patch \ " SRC_URI[sha256sum] = "c74a7a2adf861c04d002db713dd85f84beb242228e671280bf709d765b03672b" -- 2.35.6