Unverified 3D callbacks in mews/pos let attackers forge payments
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-345.
Summary
mews/pos through 2.0.0 accepts payment callbacks without verifying their data authenticity (CWE-345). The GarantiPos, PayForPos and InterPos 3D Pay and 3D Host handlers skip the hash check, so an unauthenticated remote attacker can post altered status, amount or order ID values and complete orders without paying.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Description from the CNA
mews/pos through 2.0.0 contains an insufficient verification of data authenticity vulnerability that allows unauthenticated attackers to forge payment results by submitting unverified callbacks. GarantiPos, PayForPos and InterPos 3D Pay and 3D Host handlers skip check3DHash(), letting attackers post tampered status, amount or order ID fields to complete orders without paying.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| mewebstudio | pos | up to 2.0.0 | — | No fix listed | CNA |
- pos Vendormewebstudio Affected up to 2.0.0 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for mews/pos.
Written with Claude Haiku 5.5 from the sources below · 2026-11-04
Timeline
- 2026-10-28 Threatist record created from CVE-2026-118377
- 2026-10-28 Alias added: GHSA-qfwr-rmpq-mvmx
- 2026-10-28 Priority changed: MEDIUM → LOW
- 2026-11-04 CISA SSVC decision points changed
- 2026-11-04 Priority changed: LOW → MEDIUM
References
Patch 2
Other 4
- https://github.com/mewebstudio/pos/issues/306
- https://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/PayForPos.php#L135-L150
- https://github.com/mewebstudio/pos/blob/50ed2bfe4f8980b8b0c47996de571943fa58d7ad/src/Gateway/InterPos.php#L134-L149
- https://github.com/mewebstudio/pos
Sources
- CVE-2026-118377 · CVE Program
- CVE-2026-118377 · NVD
- FIRST EPSS
- GHSA-qfwr-rmpq-mvmx · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences