Płatnik: Use of Client-Side Authentication
CVE-2026-110972 is a high-severity use of client-side authentication vulnerability in Płatnik from Zakład Ubezpieczeń Społecznych, with a CVSS 4.0 base score of 8.6 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. Affected Płatnik versions: 10.02.002 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Płatnik you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Zakład Ubezpieczeń Społecznych | Płatnik | 10.02.002 and earlier | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- LowLimited loss of availability on the vulnerable system.
- Confidentiality (other systems)
- NoneNo loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- NoneNo loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- NoneNo loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/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. Scored by CNA (cert.pl).
Official description
Płatnik performs client-side authentication. An attacker with access to any application instance connected to the backend server can bypass the login verification process and authenticate as an arbitrary user. This issue was fixed in metric 334 in version 10.02.002.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Client-Side Authentication
A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.
How developers prevent this class of flaw
- Do not rely on client side data. Always perform server side authentication.
More Use of Client-Side Authentication vulnerabilities (CWE-603)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Płatnik
- 7.7 High severity
Recent Use of Client-Side Authentication vulnerabilities
- 8.2 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.7 High severity
- 8.4 High severity
- 7.8 High severity
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