Evidence used
- No CISA KEV confirmation is currently recorded.
- The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
- EPSS is 0.94% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2026
CVE-2026-28387High confidence
Potential Use-after-free in DANE Client Code
OpenSSL · OpenSSL
8.1HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:High, unchanged from published severity.unchanged
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict the affected network interface to trusted sources where business-safe.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs OpenSSL OpenSSL and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Siemens ProductCERT: 1 affected or under-investigation product state without a fixed product state in the same current advisory
- Siemens ProductCERT: 1 affected or under-investigation product state without a fixed product state in the same current advisory
Distribution package intelligence
9 package statesRelease-specific package status
Alpine, Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Alpine v3.23v3.23 · main | openssl | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 3.5.6-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.22v3.22 · main | openssl | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 3.5.6-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Alpine v3.21v3.21 · main | openssl | Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected. | 3.3.7-r0 | Alpine Security Database ↗Source updated 3 Oct 2026 |
| Debian trixietrixie · source | openssl | Vendor fix publishedDebian records a fixed source-package version for this release. | 3.5.5-1~deb13u2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian bookwormbookworm · source | openssl | Vendor fix publishedDebian records a fixed source-package version for this release. | 3.0.19-1~deb12u2 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian forkyforky · source | openssl | Vendor fix publishedDebian records a fixed source-package version for this release. | 3.6.2-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Debian sidsid · source | openssl | Vendor fix publishedDebian records a fixed source-package version for this release. | 3.6.2-1 | Debian Security Tracker ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | edk2 | Under evaluationCanonical reports that the package might be affected and still needs evaluation or fixing. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | openssl | Vendor fix publishedCanonical reports that a fixed source package version has been published. Repository candidate availability is not checked by BlackTree. | 3.0.13-0ubuntu3.9 | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
Direct vendor intelligence
3 currentAuthoritative 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.
CVE-2026-28387 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityopenssl: OpenSSL: Arbitrary code execution due to use-after-free in DANE TLSA authentication
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. An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. This vulnerability could lead to data corruption, application crashes, or, in severe cases, arbitrary code execution. This issue is highly specific and uncommon, as it only affects clients using both PKIX-TA(0)/PKIX-EE(1) and DANE-TA(2) certificate usages and communicating with a server publishing a TLSA record set with both types of records.
- Remediation
- For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
SSA-032379 · CSAF 2.0 · revision 1 · interimSiemens ProductCERTSSA-032379: Multiple Vulnerabilities in SIMATIC CN 4100 Before V5.0
The vendor explicitly identifies these products as affected by this CVE.
- SIMATIC CN 4100
- Summary
- Issue summary: An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, the issue only affects clients that make use of TLSA records with both the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate usage. By far the most common deployment of DANE is in SMTP MTAs for which RFC7672 recommends that clients treat as 'unusable' any TLSA records that have the PKIX certificate usages. These SMTP (or other similar) clients are not vulnerable to this issue. Conversely, any clients that support only the PKIX usages, and ignore the DANE-TA(2) usage are also not vulnerable. The client would also need to be communicating with a server that publishes a TLSA RRset with both types of TLSA records. No FIPS modules are affected by this issue, the problem code is outside the FIPS module boundary.
- Remediation
- Update to V5.0 or later version
SSA-265688 · CSAF 2.0 · revision 13 · interimSiemens ProductCERTSSA-265688: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1
The vendor explicitly identifies these products as affected by this CVE.
- SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
- Summary
- Issue summary: An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, the issue only affects clients that make use of TLSA records with both the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate usage. By far the most common deployment of DANE is in SMTP MTAs for which RFC7672 recommends that clients treat as 'unusable' any TLSA records that have the PKIX certificate usages. These SMTP (or other similar) clients are not vulnerable to this issue. Conversely, any clients that support only the PKIX usages, and ignore the DANE-TA(2) usage are also not vulnerable. The client would also need to be communicating with a server that publishes a TLSA RRset with both types of TLSA records. No FIPS modules are affected by this issue, the problem code is outside the FIPS module boundary.
- Remediation
- Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
Issue summary: An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, the issue only affects clients that make use of TLSA records with both the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate usage. By far the most common deployment of DANE is in SMTP MTAs for which RFC7672 recommends that clients treat as 'unusable' any TLSA records that have the PKIX certificate usages. These SMTP (or other similar) clients are not vulnerable to this issue. Conversely, any clients that support only the PKIX usages, and ignore the DANE-TA(2) usage are also not vulnerable. The client would also need to be communicating with a server that publishes a TLSA RRset with both types of TLSA records. No FIPS modules are affected by this issue, the problem code is outside the FIPS module boundary.
What
Issue summary: An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, the issue only affects clients that make use of TLSA records with both the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate usage. By far the most common deployment of DANE is in SMTP MTAs for which RFC7672 recommends that clients treat as 'unusable' any TLSA records that have the PKIX certificate usages. These SMTP (or other similar) clients are not vulnerable to this issue. Conversely, any clients that support only the PKIX usages, and ignore the DANE-TA(2) usage are also not vulnerable. The client would also need to be communicating with a server that publishes a TLSA RRset with both types of TLSA records. No FIPS modules are affected by this issue, the problem code is outside the FIPS module boundary.
Why
The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
What
Issue summary: An uncommon configuration of clients performing DANE TLSA-based server authentication, when paired with uncommon server DANE TLSA records, may result in a use-after-free and/or double-free on the client side. Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, the issue only affects clients that make use of TLSA records with both the PKIX-TA(0/PKIX-EE(1) certificate usages and the DANE-TA(2) certificate usage. By far the most common deployment of DANE is in SMTP MTAs for which RFC7672 recommends that clients treat as 'unusable' any TLSA records that have the PKIX certificate usages. These SMTP (or other similar) clients are not vulnerable to this issue. Conversely, any clients that support only the PKIX usages, and ignore the DANE-TA(2) usage are also not vulnerable. The client would also need to be communicating with a server that publishes a TLSA RRset with both types of TLSA records. No FIPS modules are affected by this issue, the problem code is outside the FIPS module boundary.
Why
The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.
How
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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 None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.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
- a network path → Use After Free → execute code or commands in the affected security context
- Attack surface
- Network
- Privileges required
- None: unauthenticated exploitation is possible
- User interaction
- None
- Attack complexity
- High: exploitation depends on specific conditions
- 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-416 ↗
CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACHighAttack complexity: Successful exploitation depends on specific conditions outside the attacker's direct control.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.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
03
Patch and workaround
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. - Fix availability varies by product
- 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
- openssl as a component of Red Hat Enterprise Linux 7
- openssl-devel as a component of Red Hat Enterprise Linux 7
- openssl-libs as a component of Red Hat Enterprise Linux 7
- openssl-perl as a component of Red Hat Enterprise Linux 7
- openssl-static as a component of Red Hat Enterprise Linux 7
- openssl.src 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
- and 40 more
- Fixed
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04
Evidence and provenance
Published 7 Apr 2026 · Last source change 12 May 2026, 12:08 UTC · CWE-416 · Use After Free
CVE recordCVE.org · 5.2
CVSS sourceNIST NVD
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2026-19961
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment
Core structured fields are present and their contributing authorities are shown above.
Material change intelligence
View recent updates ↗What changed after publication
- Affected versionsThe structured affected or fixed version information changed.Red Hat Product Security ↗
- Before
- 3.6.0 < 3.6.2; 3.5.0 < 3.5.6; 3.4.0 < 3.4.5; 3.3.0 < 3.3.7; 3.0.0 < 3.0.20; 1.1.1 < 1.1.1zg · 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.
- After
- 3.6.0 < 3.6.2; 3.5.0 < 3.5.6; 3.4.0 < 3.4.5; 3.3.0 < 3.3.7; 3.0.0 < 3.0.20; 1.1.1 < 1.1.1zg · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
- Affected versionsThe structured affected or fixed version information changed.Red Hat Product Security ↗
- Before
- Fixed: openssl-main@aarch64 as a component of Red Hat Hardened Images; openssl-main@src as a component of Red Hat Hardened Images; openssl-main@x86_64 as a component of Red Hat Hardened Images
- 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; openssl as a component of Red Hat Enterprise Linux 7; openssl-devel as a component of Red Hat Enterprise Linux 7; openssl-libs as a component of Red Hat Enterprise Linux 7; openssl-perl as a component of Red Hat Enterprise Linux 7; openssl-static as a component of Red Hat Enterprise Linux 7; openssl.src 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; and 40 more · Fixed: openssl-main@aarch64 as a component of Red Hat Hardened Images; openssl-main@src as a component of Red Hat Hardened Images; openssl-main@x86_64 as a component of Red Hat Hardened Images
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
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.