PT-2026-47838 · Openssl+4 · Openssl+4

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CVE-2026-42768

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Published

2026-06-09

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Updated

2026-07-19

CVSS v3.1

3.7

Low

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Name of the Vulnerable Software and Affected Versions OpenSSL (affected versions not specified)
Description The CMS decrypt() and PKCS7 decrypt() functions are susceptible to a Bleichenbacher-style attack, which is an adaptive-chosen-ciphertext side channel. This allows an attacker to use a vulnerable application to decrypt or sign messages using the victim's private RSA key. The issue occurs in two scenarios: first, when the decryption API is used without a recipient certificate, OpenSSL iterates through every KeyTransRecipientInfo (KTRI) without stopping at the first success; second, when a recipient certificate is provided but the recipient is not found, a random key is substituted. In both cases, if an attacker can observe error codes or decryption output, they can establish an oracle to decrypt RSA ciphertexts or forge PKCS#1 v1.5 signatures.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

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Weakness Enumeration

Related Identifiers

ALSA-2026:25237
ALSA-2026:25239
CVE-2026-42768
OESA-2026-3002
OESA-2026-3003
OESA-2026-3004
OESA-2026-3005
OESA-2026-3006
OPENSUSE-SU-2026:11023-1
OPENSUSE-SU-2026:21005-1
RHSA-2026:25237
RHSA-2026:25239
SUSE-SU-2026:22251-1
SUSE-SU-2026:22315-1
SUSE-SU-2026:2648-1
USN-8414-1

Affected Products

Freebsd
Linuxmint
Openssl
Rocky Linux
Ubuntu