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CVE-2026-31790 on CTRL-OS 26.05

Aliases: CVE-2026-31790

Packages: openssl, openssl_3, openssl_3_2, openssl_3_3

Status: Resolved

Advisory Information

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.

Updates

2026-07-02 15:41 CEST

Metadata changes:

  • Status for package openssl: “Resolved” (8390a9a137608411c0e3921235f12af37c9819ec)
  • Status for package openssl_3: “Resolved” (8390a9a137608411c0e3921235f12af37c9819ec)
  • Status for package openssl_3_2: “Resolved” (8390a9a137608411c0e3921235f12af37c9819ec)
  • Status for package openssl_3_3: “Resolved” (8390a9a137608411c0e3921235f12af37c9819ec)

2026-05-29 18:50 CEST

Metadata changes:

  • Status for package openssl: “New”
  • Status for package openssl_3: “New”
  • Status for package openssl_3_2: “New”
  • Status for package openssl_3_3: “New”

(Amended on: 2026-05-29 18:51 CEST)