Upstream information
Description
Improper Following of a Certificate's Chain of Trust vulnerability in Erlang OTP public_key (pubkey_cert module) allows a non-CA certificate to be accepted as an intermediate issuer, enabling certificate chain forgery.In lib/public_key/src/pubkey_cert.erl, pubkey_cert:validate_extensions/7 contains two flaws that together allow a certificate with basicConstraints cA:false and no keyUsage extension to be used as an intermediate issuer in a chain passed to public_key:pkix_path_validation/3: the cA:false clause recurses into the remaining extensions without rejecting the certificate when it is in issuer position, and the keyUsage check only fires when the extension is present, so a certificate lacking keyUsage entirely bypasses the keyCertSign enforcement.
Any party holding an end-entity certificate with basicConstraints cA:false and no keyUsage extension, issued by any CA in the victim's trust store, can use that certificate's private key to sign forged leaf certificates for arbitrary identities. public_key:pkix_path_validation/3 accepts the resulting chain, and by extension every TLS or mTLS endpoint built on the OTP ssl application that relies on the default verifier is affected, including server identity verification on the client side and client certificate verification on mTLS servers.
This issue affects OTP from OTP 17.0 before OTP 26.2.5.21, 27.3.4.12, 28.5.0.1, and 29.0.1 corresponding to public_key from 0.22 before 1.15.1.7, 1.17.1.3, 1.20.3.1, and 1.21.1.
SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | SUSE |
|---|---|
| Base Score | 7.4 |
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N |
| Attack Vector | Network |
| Attack Complexity | High |
| Privileges Required | None |
| User Interaction | None |
| Scope | Unchanged |
| Confidentiality Impact | High |
| Integrity Impact | High |
| Availability Impact | None |
| CVSSv3 Version | 3.1 |
| CVSS detail | CNA (6b3ad84c-e1a6-4bf7-a703-f496b71e49db) | SUSE |
|---|---|---|
| Base Score | 7 | 9.1 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Attack Requirements | Present | Present |
| Privileges Required | None | None |
| User Interaction | None | None |
| Vulnerable System Confidentiality Impact | Low | High |
| Vulnerable System Integrity Impact | Low | High |
| Vulnerable System Availability Impact | None | None |
| Subsequent System Confidentiality Impact | High | None |
| Subsequent System Integrity Impact | High | None |
| Subsequent System Availability Impact | None | None |
| CVSSv4 Version | 4.0 | 4.0 |
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP7 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | erlang26 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP7 | erlang26 | Affected |
| SUSE Linux Enterprise Server 15 SP7 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP7 | erlang26 | Affected |
| SUSE Linux Enterprise Server 16.0 | erlang | Affected |
| SUSE Linux Enterprise Server 16.1 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | erlang26 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.0 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | erlang | Affected |
| openSUSE Leap 16.0 | erlang | Affected |
| Products under Long Term Service Pack support and receiving important and critical security fixes. | ||
| SUSE Linux Enterprise High Performance Computing 15 SP4 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP4 | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP5 | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP6 | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP6 | erlang26 | Affected |
| SUSE Linux Enterprise Server 15 SP4 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP4-LTSS | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP5 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP5-LTSS | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP6 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP6 | erlang26 | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP6-LTSS | erlang26 | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | erlang26 | Affected |
| SUSE Manager Proxy 4.3 | erlang | Affected |
| SUSE Manager Proxy LTS 4.3 | erlang | Affected |
| SUSE Manager Retail Branch Server 4.3 | erlang | Affected |
| SUSE Manager Retail Branch Server LTS 4.3 | erlang | Affected |
| SUSE Manager Server 4.3 | erlang | Affected |
| SUSE Manager Server LTS 4.3 | erlang | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Enterprise Storage 7 | erlang | Affected |
| SUSE Enterprise Storage 7.1 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | erlang | Affected |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | erlang26 | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP2 | erlang | Affected |
| SUSE Linux Enterprise Module for Server Applications 15 SP3 | erlang | Affected |
| SUSE Linux Enterprise Real Time 15 SP2 | erlang | Affected |
| SUSE Linux Enterprise Real Time 15 SP3 | erlang | Affected |
| SUSE Linux Enterprise Real Time 15 SP4 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP2 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP2-BCL | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP2-LTSS | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP3 | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP3-BCL | erlang | Affected |
| SUSE Linux Enterprise Server 15 SP3-LTSS | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | erlang | Affected |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | erlang | Affected |
| SUSE Manager Proxy 4.1 | erlang | Affected |
| SUSE Manager Proxy 4.2 | erlang | Affected |
| SUSE Manager Retail Branch Server 4.1 | erlang | Affected |
| SUSE Manager Retail Branch Server 4.2 | erlang | Affected |
| SUSE Manager Server 4.1 | erlang | Affected |
| SUSE Manager Server 4.2 | erlang | Affected |
| openSUSE Leap 15.3 | erlang | Affected |
| openSUSE Leap 15.4 | erlang | Affected |
| openSUSE Leap 15.5 | erlang | Affected |
| openSUSE Leap 15.6 | erlang | Affected |
| openSUSE Leap 15.6 | erlang26 | Affected |
SUSE Timeline for this CVE
CVE page created: Wed May 27 16:20:29 2026CVE page last modified: Wed May 27 21:28:13 2026