TillKit WordPress plugin: Authentication bypass via hard-coded default PIN
Summary
The TillKit WordPress plugin turns a WooCommerce store into a mobile point of sale (POS). On activation it creates a privileged POS account protected by a hard-coded, publicly known PIN that does not have to be changed before use. The public POS login checks only this PIN, so an unauthenticated attacker can obtain a privileged POS session, read customer and site-user personal data and modify store data. WPScan rates the issue 8.1 and the CVE record 8.2 (CVSS 3.1).
Affected
- TillKit WordPress plugin, all versions before 1.0.5 (VulDB states up to 1.0.4)
Fixed in
- Update to TillKit 1.0.5 or later
Workaround
Unknown. The sources reviewed do not describe a workaround.
Exploitation
- Not listed in CISA KEV at the time of the sources.
- CISA SSVC assessment: exploitation none, automatable yes, technical impact partial.
- No public proof of concept confirmed.
- No exploitation in the wild known.
- EPSS values conflict between sources.
Our recommendation
- Inventory all WordPress/WooCommerce sites for TillKit and check the installed version.
- Update to 1.0.5 or later, or disable the plugin until the update is applied.
- If an update is not possible immediately, restrict access to the POS login path at the web server or WAF (this is a research recommendation, not stated by a source).
- Review POS login logs and customer data access, and check whether the hard-coded PIN account still exists.
- Include publicly reachable staging sites in the check.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- WPScan: TillKit < 1.0.5 - Unauthenticated POS Takeover wpscan.com
- VulDB: CVE-2026-91078 vuldb.com
- WordPress.org: TillKit plugin wordpress.org
- GitHub: CVE issue 1161 (EPSS and KEV status) github.com
- Positive Technologies: PT-2026-104530 vulners.com
- Rapid7 aggregation via Vulners: CVE-2026-91078 vulners.com
- CVE aggregator: CVE-2026-91078 cve.threatint.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 1 Nov 2026, 17:06.
Original description (NVD)
The TillKit WordPress plugin before 1.0.5 does not require the hard-coded, publicly known PIN of the privileged POS account it creates on activation to be changed before use, and it authenticates its public POS login endpoint on that PIN alone with no identity or capability check, allowing unauthenticated attackers to obtain a privileged POS session and thereby read customer and site-user personal data and modify store data.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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