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NVD / CVE Program· CNA openssl

CVE-2026-42771: Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()

Noroxi assessment

Priority: Monitor (action score 24/100)

  • 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: 0.21% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: OpenSSL OpenSSL 4.0.1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to OpenSSL OpenSSL 4.0.1 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 the X509_VERIFY_PARAM_set1_email is called by an application to validate a crafted e-mail address, such as during S/MIME message validation, an out of bounds read can happen. Impact summary: This out of bounds read will not directly exfiltrate the data read to the attacker so the most likely result is a crash and a Denial of Service. An internal helper function called from X509_VERIFY_PARAM_[set|add]_email() used a wrong length when validating the local part of an email address. This could cause the 64 octet limit on the local part of an email address to be not enforced, or cause an out of bound read and potentially a crash. The bug is reachable via S-MIME validation with a crafted From: address supplied in an email message that can potentially cause a crash. No FIPS modules are affected by this issue as the affected code is outside the OpenSSL FIPS module boundary.

MediumCVSS 6.2 · v3.1—No exploit Fix available
Published
Jun 9, 2026
Updated
Jul 23, 2026
EPSS
0.2% · 12th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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

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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 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

Package-level exposure

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

EcosystemPackageAffected rangeFix
Red Hat:hummingbird:1bootupdbefore 0:0.3.2-1.hum10:0.3.2-1.hum1
Red Hat:hummingbird:1chunkahbefore 0:0.6.0-3.hum10:0.6.0-3.hum1
Red Hat:hummingbird:1opensslbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-config-fipsbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-develbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-devel-enginebefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-fips-provider-upstreambefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-libsbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl-perlbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl3before 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl3-develbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl3-devel-enginebefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1openssl3-libsbefore 0:3.5.8-0.1.hum10:3.5.8-0.1.hum1
Red Hat:hummingbird:1python-cryptographybefore 0:50.0.0-1.hum10:50.0.0-1.hum1
Red Hat:hummingbird:1python3-cryptographybefore 0:50.0.0-1.hum10:50.0.0-1.hum1
Red Hat:hummingbird:1ruby3.3before 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-bundled-gemsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-default-gemsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-develbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-docbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.3-libsbefore 0:3.3.10-23.6.hum10:3.3.10-23.6.hum1
Red Hat:hummingbird:1ruby3.4before 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-bundled-gemsbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1
Red Hat:hummingbird:1ruby3.4-default-gemsbefore 0:3.4.10-31.7.hum10:3.4.10-31.7.hum1

+46

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-2026-42769Jun 9, 2026 · Trust-Anchor Substitution via cert/issuer Typo in CMP rootCaKeyUpdate
    21Monitor
  • ← EarlierCVE-2026-42770Jun 9, 2026 · FFC-DH Peer Validation Uses Attacker-Supplied q
    14Monitor
  • Later →CVE-2026-45445Jun 9, 2026 · AES-OCB IV Ignored on EVP_Cipher() Path
    30Monitor

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 OpenSSL4.0.1Vendor (CNA)
red hat:chunkah0:0.6.0-3.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl-config-fips0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl-devel0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl-devel-engine0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl-fips-provider-upstream0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package 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:openssl3-devel-engine0:3.5.8-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:openssl3-libs0:3.5.8-0.1.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)

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-2026-84782112 days apartDTLS Retransmits Handshake Messages From a Stale Buffer Offset
    32Monitor
  • CVE-2026-341800 days apartHeap Buffer Over-read in ASN.1 Content Parsing
    30Monitor
  • CVE-2026-90760 days apartOut-of-Bounds Read in CMS Password-Based Decryption
    30Monitor
  • CVE-2026-2838663 days apartOut-of-bounds Read in AES-CFB-128 on X86-64 with AVX-512 Support
    30Monitor
  • CVE-2025-9230252 days apartOut-of-bounds read & write in RFC 3211 KEK Unwrap
    30Monitor
  • CVE-2025-9232252 days apartOut-of-bounds read in HTTP client no_proxy handling
    24Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records