CVE-2026-74893 in openssl_encrypt
Summary
by MITRE • 08/17/2026
openssl_encrypt versions before 1.4.0 contain hardcoded default JWT signing secrets in config.py that pass validation checks. Attackers with access to source code can forge valid JWT tokens for any client_id to gain authenticated access to keyserver and telemetry APIs.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 08/17/2026
The vulnerability identified involves a critical implementation flaw within the openssl_encrypt library prior to version 1.4.0, specifically concerning the management of JSON Web Token signing secrets. The core issue stems from hardcoded default values for JWT signing keys located in the config.py file. These defaults are not only static but also fail to undergo proper validation checks during initialization or runtime configuration loading. This design oversight means that any instance of the software deployed with these default configurations will utilize predictable, unchanging cryptographic material for token generation and verification. In secure application development, secrets such as signing keys must be unique per deployment, randomly generated, and kept confidential. The presence of hardcoded defaults violates fundamental security principles by removing entropy from the authentication mechanism, thereby rendering the integrity checks provided by JWT signatures ineffective against adversaries who possess knowledge of these static values.
From a technical perspective, this flaw allows for complete bypassing of authentication mechanisms that rely on signed tokens. An attacker with access to the source code can easily extract the hardcoded signing secret and use it to construct valid JSON Web Tokens for any arbitrary client_id. Since the verification process relies solely on checking the signature against this known key, the forged token will be accepted as legitimate by both the keyserver API and telemetry APIs. This effectively grants the attacker authenticated access without requiring valid credentials or possession of a real user session. The vulnerability is particularly severe because it affects the foundational trust model of the application; once an attacker can forge tokens for any client_id, they assume full control over that identity within the system context.
The operational impact of this vulnerability is significant and wide-ranging. By forging JWTs, an adversary can impersonate legitimate clients to interact with sensitive backend services. Accessing the keyserver API could allow the extraction or manipulation of cryptographic keys used for further encryption operations, potentially compromising data at rest or in transit across the entire system. Similarly, access to telemetry APIs might enable the injection of false metrics, masking malicious activities or causing operational disruptions through misleading analytics. Furthermore, if these APIs have administrative privileges or can trigger actions on behalf of other users, the attacker could perform unauthorized state changes, escalate privileges, or exfiltrate sensitive data associated with those client identities. This represents a total compromise of authentication integrity for any system running the affected version without custom configuration overrides.
This vulnerability aligns closely with CWE-798: Use of Hard-coded Credentials and CWE-204: Observable Response Discrepancy if validation failures are not handled uniformly, though primarily it is classified under CWE-321: Use of a Key Past its Expiration Date or more accurately CWE-613: Insufficient Session Expiration. In terms of the MITRE ATT&CK framework, this flaw facilitates Initial Access via Valid Accounts (T1078) and potentially Privilege Escalation if higher-level client IDs can be forged. It also supports Defense Evasion by allowing attackers to operate under legitimate-looking credentials that bypass standard logging or anomaly detection systems designed for unknown actors.
To mitigate this vulnerability, organizations must immediately upgrade openssl_encrypt to version 1.4.0 or later where these hardcoded defaults have been removed and replaced with secure generation mechanisms. For environments unable to patch immediately due to dependency constraints, a temporary mitigation involves overriding the default configuration in config.py by setting unique, high-entropy signing secrets for each deployment instance. These secrets should be generated using cryptographically secure random number generators and stored securely via environment variables or dedicated secret management systems rather than being embedded directly in source code files. Additionally, implementing strict validation checks that reject tokens signed with known public defaults can provide a layer of defense-in-depth while the underlying issue is resolved. Regular security audits focusing on configuration management practices are recommended to prevent similar hardcoding issues in other components of the application stack.