CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q
FFC-DH Peer Validation Uses Attacker-Supplied q
Other sources
Issue summary: When EVPPKEYderivesetpeer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership.
— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/opensslto a version that resolves this vulnerability.Fixed in 1.1.1w-0+deb11u1Fixed in 1.1.1w-0+deb11u7Fixed in 3.0.20-1~deb12u2Fixed in 3.5.6-1~deb13u2 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 3.3.7-4 - Upgrade
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Fixed in 3.0.21 - Upgrade
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Fixed in 3.4.6 - Upgrade
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Fixed in 3.5.7 - Upgrade
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Fixed in 3.6.3 - Upgrade
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Fixed in 4.0.1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42770?
CVE-2026-42770 has a severity rating of low with a score of 3.7.
How do I fix CVE-2026-42770?
To mitigate CVE-2026-42770, ensure that proper subgroup membership checks are applied when calling EVP_PKEY_derive_set_peer().
What impact can CVE-2026-42770 have on security?
CVE-2026-42770 allows a malicious peer to potentially exploit the lack of subgroup checks in an X9.42 key.
Which software is affected by CVE-2026-42770?
CVE-2026-42770 affects the OpenSSL FIPS Module among other OpenSSL implementations.
What should I do if I am using OpenSSL and concerned about CVE-2026-42770?
If using OpenSSL, review your implementation of EVP_PKEY_derive_set_peer() and apply the necessary checks for subgroup membership.