7.5 CVE-2026-31790

Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.
https://nvd.nist.gov/vuln/detail/CVE-2026-31790

Categories

CWE-754 : Improper Check for Unusual or Exceptional Conditions
The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. Automated static analysis may be useful for detecting unusual conditions involving system resources or common programming idioms, but not for violations of business rules. Identify error conditions that are not likely to occur during normal usage and trigger them. For example, run the program under low memory conditions, run with insufficient privileges or permissions, interrupt a transaction before it is completed, or disable connectivity to basic network services such as DNS. Monitor the software for any unexpected behavior. If you trigger an unhandled exception or similar error that was discovered and handled by the application's environment, it may still indicate unexpected conditions that were not handled by the application itself. Check the results of all functions that return a value and verify that the value is expected. If using exception handling, catch and throw specific exceptions instead of overly-general exceptions (CWE-396, CWE-397). Catch and handle exceptions as locally as possible so that exceptions do not propagate too far up the call stack (CWE-705). Avoid unchecked or uncaught exceptions where feasible (CWE-248). If the program must fail, ensure that it fails gracefully (fails closed). There may be a temptation to simply let the program fail poorly in cases such as low memory conditions, but an attacker may be able to assert control before the software has fully exited. Alternately, an uncontrolled failure could cause cascading problems with other downstream components; for example, the program could send a signal to a downstream process so the process immediately knows that a problem has occurred and has a better chance of recovery. Use system limits, which should help to prevent resource exhaustion. However, the product should still handle low resource conditions since they may still occur. Chain: function in web caching proxy does not correctly check a return value (CWE-253) leading to a reachable assertion (CWE-617) Unchecked return value leads to resultant integer overflow and code execution. Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail. Program does not check return value when invoking functions to drop privileges, which could leave users with higher privileges than expected by forcing those functions to fail.

References

 

AFFECTED (from MITRE)

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Vendor	Product	Versions
OpenSSL	OpenSSL	3.6.0 < 3.6.2 [affected] 3.5.0 < 3.5.6 [affected] 3.4.0 < 3.4.5 [affected] 3.3.0 < 3.3.7 [affected] 3.0.0 < 3.0.20 [affected]
© 2022 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.

CPE

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REMEDIATION

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EXPLOITS

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Exploit-db.com

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POC Github

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Other Nist (github, ...)

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CAPEC

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Common Attack Pattern Enumerations and Classifications

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