Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
OpenSSL · OpenSSL
6.2MediumCVSS 3.1
Recommended action
Scheduled
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available
Direct vendor intelligence
Authoritative vendor CSAF and VEX advisories
Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.
1 current
CVE-2026-42771 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityopenssl: Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email()
58 known affected
The vendor explicitly identifies these products as affected by this CVE.
edk2-aarch64 as a component of Red Hat Enterprise Linux 10
edk2-ovmf as a component of Red Hat Enterprise Linux 10
edk2-tools as a component of Red Hat Enterprise Linux 10
edk2-tools-doc as a component of Red Hat Enterprise Linux 10
edk2.src as a component of Red Hat Enterprise Linux 10
mokutil as a component of Red Hat Enterprise Linux 10
openssl as a component of Red Hat Enterprise Linux 10
openssl-devel as a component of Red Hat Enterprise Linux 10
openssl-libs as a component of Red Hat Enterprise Linux 10
openssl-perl as a component of Red Hat Enterprise Linux 10
openssl.src as a component of Red Hat Enterprise Linux 10
shim-aa64 as a component of Red Hat Enterprise Linux 10
Summary
A flaw was found in OpenSSL. When an application uses the X509_VERIFY_PARAM_set1_email() function to validate a specially crafted S/MIME (Secure/Multipurpose Internet Mail Extensions) email address, an out-of-bounds read can occur. A remote attacker could exploit this vulnerability by sending a malicious email, leading to an application crash and a Denial of Service (DoS). This issue does not directly expose sensitive data.
Remediation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Optional official sources
National CERT insights ?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.
Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.
Official European source
ENISA European Vulnerability Database
Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.
1 current
ENISA EUVD identifier
EUVD-2026-35488
No EUVD known-exploited evidence
ENISA has published the identifier mapping but no EUVD description has been stored yet.
EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionScheduled
Medium technical severity with no CISA KEV confirmation; remediate through the normal risk-based patch cycle unless local exposure raises the priority.
Patch available
01
What, why and how
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.
What
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.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
What
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.
Why
The product reads data past the end, or before the beginning, of the intended buffer.
How
An attacker operating through local access may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No confirmed evidence
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material ?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.None recorded
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
Likely attack path
local access → Out-of-bounds Read → disrupt the affected service
Attack surface
Local
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness ?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-125: Out-of-bounds Read. The product reads data past the end, or before the beginning, of the intended buffer.
CVSS vector ?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
UnauthenticatedDenial of serviceCWE-125
A
Official authority intelligence
Only matched European and national findings are included. Language selectors and unavailable sources are omitted.
ENISA EUVD · EUVD-2026-35488Official EUVD mapping
0 linked advisory records.
Official EUVD recordBSI · German · WID-SEC-W-2026-2919IBM App Connect Enterprise: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in IBM App Connect Enterprise ausnutzen, um beliebigen Programmcode auszuführen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um Informationen offenzulegen, um Dateien zu manipulieren, um einen Cross-Site Scripting Angriff durchzuführen, und um Sicherheitsvorkehrungen zu umgehen.
Official advisoryBSI · German · WID-SEC-W-2026-2455Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in verschiedenen Komponenten von Drittanbietern in Oracle Solaris ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
Official advisoryBSI · German · WID-SEC-W-2026-1852OpenSSL: Mehrere Schwachstellen
Ein Angreifer kann mehrere Schwachstellen in OpenSSL ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsmaßnahmen zu umgehen, vertrauliche Informationen offenzulegen, Daten zu manipulieren oder einen Denial-of-Service-Zustand zu verursachen.
Official advisoryCERT-FR · French · CERTFR-2026-AVI-0796Multiples vulnérabilités dans Tenable Identity Exposure
Official advisoryCERT-FR · French · CERTFR-2026-AVI-0717Multiples vulnérabilités dans OpenSSL
De multiples vulnérabilités ont été découvertes dans OpenSSL. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et une atteinte à la confidentialité des données.
Operational remediation based on structured source evidence.
Status ?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
edk2-aarch64 as a component of Red Hat Enterprise Linux 10; edk2-ovmf as a component of Red Hat Enterprise Linux 10; edk2-tools as a component of Red Hat Enterprise Linux 10; edk2-tools-doc as a component of Red Hat Enterprise Linux 10; edk2.src as a component of Red Hat Enterprise Linux 10; mokutil as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 10; openssl-devel as a component of Red Hat Enterprise Linux 10; openssl-libs as a component of Red Hat Enterprise Linux 10; openssl-perl as a component of Red Hat Enterprise Linux 10; openssl.src as a component of Red Hat Enterprise Linux 10; shim-aa64 as a component of Red Hat Enterprise Linux 10; shim-unsigned-aarch64.src as a component of Red Hat Enterprise Linux 10; shim-unsigned-x64.src as a component of Red Hat Enterprise Linux 10; shim-x64 as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 6; openssl-devel as a component of Red Hat Enterprise Linux 6; openssl-perl as a component of Red Hat Enterprise Linux 6; openssl-static as a component of Red Hat Enterprise Linux 6; openssl.src as a component of Red Hat Enterprise Linux 6; AAVMF as a component of Red Hat Enterprise Linux 7; OVMF as a component of Red Hat Enterprise Linux 7; ovmf.src as a component of Red Hat Enterprise Linux 7; compat-openssl10 as a component of Red Hat Enterprise Linux 8; compat-openssl10.src as a component of Red Hat Enterprise Linux 8; edk2-aarch64 as a component of Red Hat Enterprise Linux 8; edk2-ovmf as a component of Red Hat Enterprise Linux 8; edk2.src as a component of Red Hat Enterprise Linux 8; mingw-openssl.src as a component of Red Hat Enterprise Linux 8; mingw32-openssl as a component of Red Hat Enterprise Linux 8; and 28 more
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
04
Evidence and provenance
Published 9 Jun 2026 · Last source change 10 Jun 2026, 07:48 UTC · CWE-125 · Out-of-bounds Read
CVE recordCVE.org · 5.2
CVSS sourceCISA ADP
EPSS source ?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-35488
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD enriched
Core structured fields are present and their contributing authorities are shown above.
Affected versionsThe structured affected or fixed version information changed.
Before
edk2-aarch64 as a component of Red Hat Enterprise Linux 10; edk2-ovmf as a component of Red Hat Enterprise Linux 10; edk2-tools as a component of Red Hat Enterprise Linux 10; edk2-tools-doc as a component of Red Hat Enterprise Linux 10; edk2.src as a component of Red Hat Enterprise Linux 10; mokutil as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 10; openssl-devel as a component of Red Hat Enterprise Linux 10; openssl-libs as a component of Red Hat Enterprise Linux 10; openssl-perl as a component of Red Hat Enterprise Linux 10; openssl.src as a component of Red Hat Enterprise Linux 10; shim-aa64 as a component of Red Hat Enterprise Linux 10; shim-unsigned-aarch64.src as a component of Red Hat Enterprise Linux 10; shim-unsigned-x64.src as a component of Red Hat Enterprise Linux 10; shim-x64 as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 6; openssl-devel as a component of Red Hat Enterprise Linux 6; openssl-perl as a component of Red Hat Enterprise Linux 6; openssl-static as a component of Red Hat Enterprise Linux 6; openssl.src as a component of Red Hat Enterprise Linux 6; AAVMF as a component of Red Hat Enterprise Linux 7; OVMF as a component of Red Hat Enterprise Linux 7; ovmf.src as a component of Red Hat Enterprise Linux 7; compat-openssl10 as a component of Red Hat Enterprise Linux 8; compat-openssl10.src as a component of Red Hat Enterprise Linux 8; edk2-aarch64 as a component of Red Hat Enterprise Linux 8; edk2-ovmf as a component of Red Hat Enterprise Linux 8; edk2.src as a component of Red Hat Enterprise Linux 8; mingw-openssl.src as a component of Red Hat Enterprise Linux 8; mingw32-openssl as a component of Red Hat Enterprise Linux 8; and 27 more
After
edk2-aarch64 as a component of Red Hat Enterprise Linux 10; edk2-ovmf as a component of Red Hat Enterprise Linux 10; edk2-tools as a component of Red Hat Enterprise Linux 10; edk2-tools-doc as a component of Red Hat Enterprise Linux 10; edk2.src as a component of Red Hat Enterprise Linux 10; mokutil as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 10; openssl-devel as a component of Red Hat Enterprise Linux 10; openssl-libs as a component of Red Hat Enterprise Linux 10; openssl-perl as a component of Red Hat Enterprise Linux 10; openssl.src as a component of Red Hat Enterprise Linux 10; shim-aa64 as a component of Red Hat Enterprise Linux 10; shim-unsigned-aarch64.src as a component of Red Hat Enterprise Linux 10; shim-unsigned-x64.src as a component of Red Hat Enterprise Linux 10; shim-x64 as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 6; openssl-devel as a component of Red Hat Enterprise Linux 6; openssl-perl as a component of Red Hat Enterprise Linux 6; openssl-static as a component of Red Hat Enterprise Linux 6; openssl.src as a component of Red Hat Enterprise Linux 6; AAVMF as a component of Red Hat Enterprise Linux 7; OVMF as a component of Red Hat Enterprise Linux 7; ovmf.src as a component of Red Hat Enterprise Linux 7; compat-openssl10 as a component of Red Hat Enterprise Linux 8; compat-openssl10.src as a component of Red Hat Enterprise Linux 8; edk2-aarch64 as a component of Red Hat Enterprise Linux 8; edk2-ovmf as a component of Red Hat Enterprise Linux 8; edk2.src as a component of Red Hat Enterprise Linux 8; mingw-openssl.src as a component of Red Hat Enterprise Linux 8; mingw32-openssl as a component of Red Hat Enterprise Linux 8; and 28 more
Affected versionsThe structured affected or fixed version information changed.
Before
edk2-aarch64 as a component of Red Hat Enterprise Linux 10; edk2-ovmf as a component of Red Hat Enterprise Linux 10; edk2-tools as a component of Red Hat Enterprise Linux 10; edk2-tools-doc as a component of Red Hat Enterprise Linux 10; edk2.src as a component of Red Hat Enterprise Linux 10; mokutil as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 10; openssl-devel as a component of Red Hat Enterprise Linux 10; openssl-libs as a component of Red Hat Enterprise Linux 10; openssl-perl as a component of Red Hat Enterprise Linux 10; openssl.src as a component of Red Hat Enterprise Linux 10; shim-aa64 as a component of Red Hat Enterprise Linux 10; shim-unsigned-aarch64.src as a component of Red Hat Enterprise Linux 10; shim-unsigned-x64.src as a component of Red Hat Enterprise Linux 10; shim-x64 as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 6; openssl-devel as a component of Red Hat Enterprise Linux 6; openssl-perl as a component of Red Hat Enterprise Linux 6; openssl-static as a component of Red Hat Enterprise Linux 6; openssl.src as a component of Red Hat Enterprise Linux 6; AAVMF as a component of Red Hat Enterprise Linux 7; OVMF as a component of Red Hat Enterprise Linux 7; ovmf.src as a component of Red Hat Enterprise Linux 7; compat-openssl10 as a component of Red Hat Enterprise Linux 8; compat-openssl10.src as a component of Red Hat Enterprise Linux 8; edk2-aarch64 as a component of Red Hat Enterprise Linux 8; edk2-ovmf as a component of Red Hat Enterprise Linux 8; edk2.src as a component of Red Hat Enterprise Linux 8; mingw32-openssl as a component of Red Hat Enterprise Linux 8; mingw64-openssl as a component of Red Hat Enterprise Linux 8; and 26 more
After
edk2-aarch64 as a component of Red Hat Enterprise Linux 10; edk2-ovmf as a component of Red Hat Enterprise Linux 10; edk2-tools as a component of Red Hat Enterprise Linux 10; edk2-tools-doc as a component of Red Hat Enterprise Linux 10; edk2.src as a component of Red Hat Enterprise Linux 10; mokutil as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 10; openssl-devel as a component of Red Hat Enterprise Linux 10; openssl-libs as a component of Red Hat Enterprise Linux 10; openssl-perl as a component of Red Hat Enterprise Linux 10; openssl.src as a component of Red Hat Enterprise Linux 10; shim-aa64 as a component of Red Hat Enterprise Linux 10; shim-unsigned-aarch64.src as a component of Red Hat Enterprise Linux 10; shim-unsigned-x64.src as a component of Red Hat Enterprise Linux 10; shim-x64 as a component of Red Hat Enterprise Linux 10; openssl as a component of Red Hat Enterprise Linux 6; openssl-devel as a component of Red Hat Enterprise Linux 6; openssl-perl as a component of Red Hat Enterprise Linux 6; openssl-static as a component of Red Hat Enterprise Linux 6; openssl.src as a component of Red Hat Enterprise Linux 6; AAVMF as a component of Red Hat Enterprise Linux 7; OVMF as a component of Red Hat Enterprise Linux 7; ovmf.src as a component of Red Hat Enterprise Linux 7; compat-openssl10 as a component of Red Hat Enterprise Linux 8; compat-openssl10.src as a component of Red Hat Enterprise Linux 8; edk2-aarch64 as a component of Red Hat Enterprise Linux 8; edk2-ovmf as a component of Red Hat Enterprise Linux 8; edk2.src as a component of Red Hat Enterprise Linux 8; mingw-openssl.src as a component of Red Hat Enterprise Linux 8; mingw32-openssl as a component of Red Hat Enterprise Linux 8; and 27 more
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
CVE-2026-42771: Possible Out of Bounds Read in X509_VERIFY_PARAM_set1_email() | BlackTree
