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NVD / CVE Program· CNA openssl

CVE-2026-42770: FFC-DH Peer Validation Uses Attacker-Supplied q

Noroxi assessment

Priority: Monitor (action score 14/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.50% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: OpenSSL OpenSSL 3.0.21, 3.4.6, 3.5.7; azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 20240524git3e722403cd16-20; azl3 openssl 3.3.7-3 on Azure Linux 3.0 3.3.7-4.

Low priority for now. Upgrade to OpenSSL OpenSSL 3.0.21, 3.4.6, 3.5.7; azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.0 20240524git3e722403cd16-20; azl3 openssl 3.3.7-3 on Azure Linux 3.0 3.3.7-4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Issue summary: When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the peer key is not properly checked for the subgroup membership. Impact summary: A malicious peer which presents an X9.42 key carrying the victim's p and g parameters, a forged q = r (a small prime factor of the cofactor (p−1)/q_local), and a public value Y of order r can recover the victim's private key after a small number of key exchange attempts. When EVP_PKEY_derive_set_peer() is called with a DHX (X9.42) peer key, the subgroup membership check Y^q ≡ 1 (mod p) is performed using the peer's own q parameter, not the local key's q. The peer's domain parameters are then matched against the domain parameters of the private key, but the value of q is not compared. A malicious peer who presents an X9.42 key carrying the victim's p, g, a forged q = r (a small prime factor of the cofactor), and a public value Y of order r passes all checks. The shared secret then takes only r distinct values, leaking priv mod r. Repeating for each small-prime factor of the cofactor and combining via CRT recovers the full private key (Lim–Lee / small-subgroup-confinement attack). The realistic attack surface is narrow: principally CMP deployments with long-lived RA/CA DHX keys and bespoke enterprise or government applications using X9.42 DHX static keys with interactive protocols and therefore this issue was assigned Low severity. The FIPS modules in 4.0, 3.6, 3.5, 3.4, 3.1.2 and 3.0 are affected by this issue.

LowCVSS 3.7 · v3.1—No exploit Fix available
Published
Jun 9, 2026
Updated
Jul 23, 2026
EPSS
0.5% · 43th percentile

Report tools

JSON

Action score

14

Monitor

Low priority for now.

CVSS
14 / 40 · 3.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
opensslopenssl

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Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • openssl openssl3.0.0 and later · before 3.0.21
  • openssl openssl3.4.0 and later · before 3.4.6
  • openssl openssl3.5.0 and later · before 3.5.7
  • openssl openssl3.6.0 and later · before 3.6.3
  • openssl openssl4.0.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (openssl). Independent of NVD's CPE analysis and usually ahead of it.

  • OpenSSL OpenSSL

    • 4.0.0 and later · before 4.0.1affected · semver
    • 3.6.0 and later · before 3.6.3affected · semver
    • 3.5.0 and later · before 3.5.7affected · semver
    • 3.4.0 and later · before 3.4.6affected · semver
    • 3.0.0 and later · before 3.0.21affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10opensslbefore 1:3.5.5-4.el10_2.alma.11:3.5.5-4.el10_2.alma.1
AlmaLinux:10openssl-develbefore 1:3.5.5-4.el10_2.alma.11:3.5.5-4.el10_2.alma.1
AlmaLinux:10openssl-libsbefore 1:3.5.5-4.el10_2.alma.11:3.5.5-4.el10_2.alma.1
AlmaLinux:10openssl-perlbefore 1:3.5.5-4.el10_2.alma.11:3.5.5-4.el10_2.alma.1
AlmaLinux:9opensslbefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8
AlmaLinux:9openssl-develbefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8
AlmaLinux:9openssl-libsbefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8
AlmaLinux:9openssl-perlbefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8
Alpine:v3.21opensslfrom 3.0.0 · before 3.3.7-r13.3.7-r1
Alpine:v3.22opensslfrom 3.0.0 · before 3.5.7-r03.5.7-r0
Debian:12opensslbefore 3.0.20-1~deb12u23.0.20-1~deb12u2
Debian:13opensslbefore 3.5.6-1~deb13u23.5.6-1~deb13u2
Debian:14opensslbefore 3.6.3-13.6.3-1
openSUSE:Leap 16.0openssl-3before 3.5.0-160000.8.13.5.0-160000.8.1
openSUSE:Tumbleweedopenssl-3before 3.5.3-6.13.5.3-6.1
Red Hat:enterprise_linux:10.2opensslbefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-debuginfobefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-debugsourcebefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-develbefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-libsbefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-libs-debuginfobefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:10.2openssl-perlbefore 1:3.5.5-4.el10_21:3.5.5-4.el10_2
Red Hat:enterprise_linux:9::appstreamopenssl-debuginfobefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8
Red Hat:enterprise_linux:9::appstreamopenssl-debugsourcebefore 1:3.5.5-4.el9_81:3.5.5-4.el9_8

+84

Same product

openssl: all records

Other highest-scoring records for the same primary product.

  • CVE-2014-0160The (1) TLS and (2) DTLS implementations in OpenSSL 1.0.1 before 1.0.1g do not properly handle Heartbeat Extension packets, which allows remKEV
    90Now
  • CVE-2021-3711SM2 Decryption Buffer Overflow
    65This week
  • CVE-2003-0545Double free vulnerability in OpenSSL 0.9.7 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code
    65This week

Published before and after this one in the same product

  • ← EarlierCVE-2026-42768Jun 9, 2026 · Multi-RecipientInfo Bleichenbacher Oracle in CMS_decrypt() and PKCS7_decrypt()
    14Monitor
  • ← EarlierCVE-2026-42769Jun 9, 2026 · Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate
    21Monitor
  • Later →CVE-2026-42771Jun 9, 2026 · Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
    24Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
OpenSSL OpenSSL3.0.21Vendor (CNA)
OpenSSL OpenSSL3.4.6Vendor (CNA)
OpenSSL OpenSSL3.5.7Vendor (CNA)
OpenSSL OpenSSL3.6.3Vendor (CNA)
OpenSSL OpenSSL4.0.1Vendor (CNA)
azl3 edk2 20240524git3e722403cd16-20 on Azure Linux 3.020240524git3e722403cd16-20Microsoft (MSRC)
azl3 openssl 3.3.7-3 on Azure Linux 3.03.3.7-4 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:openssl1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:openssl-devel1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:openssl-libs1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10Package registry (OSV)
almalinux:openssl-perl1:3.5.5-4.el10_2.alma.1 · AlmaLinux:10Package registry (OSV)
alpine:openssl3.3.7-r1 · Alpine:v3.21Package registry (OSV)
debian:openssl3.0.20-1~deb12u2 · Debian:12Package registry (OSV)
opensuse:openssl-33.5.3-6.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:chunkah0:0.6.0-3.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-debuginfo1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-debugsource1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-devel1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-libs1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-libs-debuginfo1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl-perl1:3.5.5-4.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:openssl30:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl3-devel0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:python-cryptography0:50.0.0-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:python3-cryptography0:50.0.0-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
rocky linux:openssl1:3.5.5-4.el10_2 · Rocky Linux:10Package registry (OSV)
suse:openssl-33.1.4-14.1 · SUSE:Linux Micro 6.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-454450 days apartAES-OCB IV Ignored on EVP_Cipher() Path
    30Monitor
  • CVE-2026-454460 days apartIncorrect Tag Processing for Empty Messages in AES-GCM-SIV and AES-SIV modes
    19Monitor
  • CVE-2025-69418133 days apartUnauthenticated/unencrypted trailing bytes with low-level OCB function calls
    16Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • Special conditions such as timing or configuration are required.

If successful

Confidentiality
low · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-325 · Missing Cryptographic Step

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records