CVE-2026-64855hitoshyamamoto soapbar improper certificate validation
CVE-2026-64855 is a improper certificate validation in hitoshyamamoto soapbar, rated high (8.2 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
TLS certificates are not checked properly, so an attacker on the path can pose as the server. A cryptographic signature is not checked properly, so forged data is accepted.
How it is reached
An attacker can exploit it over the network, without an account, and nobody has to click anything.
What an attacker gains
A successful attack can change data or behaviour. In practice, this kind of flaw lets an attacker read or tamper with traffic, or pass a forged message as genuine.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade hitoshyamamoto soapbar to 0.13.0 or later.
- Until it is patched, keep it off the internet or behind a VPN, allowlist or authenticating proxy.
Description from NVD
soapbar is a SOAP library for Python — client, server, and WSDL handling. Prior to version 0.13.0, verify_envelope_bsp() derived its trust anchor from the message it was verifying. It read the X.509 certificate out of the caller-untrusted wsse:BinarySecurityToken, validated only that certificate's not-before / not-after dates, and then verified the signature against that same certificate. There was no CA-chain validation, no issuer/subject allowlist, and no pinning. A successful verify_envelope_bsp() therefore proved only that the envelope was signed by whoever supplied the embedded certificate — never that it was signed by a trusted party. An attacker who mints their own certificate, signs a forged envelope, and embeds that certificate in the token passes verification. Any consumer that treats a successful BSP verification as authentication can be impersonated (signature forgery / authentication bypass). verify_envelope() (which pins a caller-supplied x509_cert) was not affected — the flaw was specific to the BSP variant whose trust anchor came from the message. This issue has been patched in version 0.13.0.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- TLS termination and service-to-service channels. The flaw sits on the network path between clients and services.
- Signature checks. The flaw sits on the network path between clients and services.
Trust boundaries in play
- Internet-facing entry points. No account is needed. Any instance reachable from outside your perimeter, through a load balancer, gateway, VPN or exposed admin port, is in scope.
- On the network path between clients and services. An attacker who crosses it can read or tamper with traffic, or pass a forged message as genuine.
Questions to answer about your own systems
- Where does hitoshyamamoto soapbar run in your systems, and at which version?
- Which of those instances can be reached from the internet or partner networks?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.