PYSEC-2025-183 CVE-2025-45768
pyjwt v2.10.1 was discovered to contain weak encryption.
High
PyPI
- Severity
- 7.0 / 10
- High · CVSS 3.1
- Exploit chance (EPSS)
- 0.18%
- Chance of exploitation in the next 30 days. Higher than 7.70% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-311 Missing Encryption of Sensitive Data
- Fix
- None yet
- No fixed version published
Description
pyjwt v2.10.1 was discovered to contain weak encryption. NOTE: this is disputed by the Supplier because the key length is chosen by the application that uses the library (admittedly, library users may benefit from a minimum value and a mechanism for opting in to strict enforcement).
Affected versions
PyPI
| Package | Vulnerable | Fixed in |
|---|---|---|
| pyjwt | <= 2.10.1 |
No fix yet |
How to fix
No fixed version has been published yet. Until one is, remove or replace the package, or turn off or isolate the affected feature. This page updates when a fix ships.
Severity breakdown
CVSS 3.1 7.0
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- High
Weakness
CWE-311: Missing Encryption of Sensitive Data
The product does not encrypt sensitive or critical information before storage or transmission.
How to prevent it
- Requirements: Clearly specify which data or resources are valuable enough that they should be protected by encryption. Require that any transmission or storage of this data/resource should use well-vetted encryption algorithms.
- Architecture and Design: Ensure that encryption is properly integrated into the system design, including but not necessarily limited to: Encryption that is needed to store or transmit private data of the users of the system Encryption that is needed to protect the system itself from unauthorized disclosure or tampering Identify the separate needs and contexts for encryption: One-way (i.e., only the user or recipient needs to have the key). This can be achieved using public key cryptography, or other techniques in which the encrypting party (i.e., the product) does not need to have access to a private key. Two-way (i.e., the encryption can be automatically performed on behalf of a user, but the key must be available so that the plaintext can be automatically recoverable by that user). This requires storage of the private key in a format that is recoverable only by the user (or perhaps by the operating system) in a way that cannot be recovered by others. Using threat modeling or other techniques, assume that data can be compromised through a separate vulnerability or weakness, and determine where encryption will be most effective. Ensure that data that should be private is not being inadvertently exposed using weaknesses such as insecure permissions (CWE-732). [REF-7]
- Architecture and Design: When there is a need to store or transmit sensitive data, use strong, up-to-date cryptographic algorithms to encrypt that data. Select a well-vetted algorithm that is currently considered to be strong by experts in the field, and use well-tested implementations. As with all cryptographic mechanisms, the source code should be available for analysis. For example, US government systems require FIPS 140-2 certification. Do not develop custom or private cryptographic algorithms. They will likely be exposed to attacks that are well-understood by cryptographers. Reverse engineering techniques are mature. If the algorithm can be compromised if attackers find out how it works, then it is especially weak. Periodically ensure that the cryptography has not become obsolete. Some older algorithms, once thought to require a billion years of computing time, can now be broken in days or hours. This includes MD4, MD5, SHA1, DES, and other algorithms that were once regarded as strong. [REF-267]
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
- Implementation, Architecture and Design: When using industry-approved techniques, use them correctly. Don't cut corners by skipping resource-intensive steps (CWE-325). These steps are often essential for preventing common attacks.
- Implementation: Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
References
Issue reports
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-pxh4-856f-4h89 PyJWT: HS256/384/512 verify accepts empty HMAC key via oct JWK (PyJWK/PyJWKClient) enabling token forgery | High | Also affects pyjwt |
| GHSA-gvp8-978c-rx2q PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse | Medium | Also affects pyjwt |
| GHSA-x33g-cr3x-6449 PyJWT accepts inconsistent OKP x/d JWKs, causing public/private key identity confusion | High | Also affects pyjwt |
| GHSA-w6j9-cwv2-h6wq PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set | High | Also affects pyjwt |
| GHSA-w2cx-738m-mc7w PyJWT accepts public JWK containers as HMAC secrets | High | Also affects pyjwt |
| GHSA-r6x4-923q-g947 PyJWT BOM Bypass | High | Also affects pyjwt |
| GHSA-p4g4-x82p-q773 PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard | High | Also affects pyjwt |
| GHSA-jwrc-g2q2-pq5p PyJWT: ReDoS vulnerability when calling the `is_pem_format` function. | Medium | Also affects pyjwt |
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