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CVE-2026-16621

MEDIUM 5.3 PoC AVAILABLE

Published 2026-08-12 · Last modified 2026-08-12

The Payment Gateway for PayPal on WooCommerce WordPress plugin before 9.2.1 does not verify that payment actually succeeded before completing an order in its PayPal return handler: it reads attacker-controlled parameters, performs no amount comparison and no order-ownership check, and completes the order even when the server-side gateway verification fails, allowing an unauthenticated attacker to mark arbitrary orders as paid without paying.

EXPLOIT AVAILABLE

Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 2nd percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

5.3CVSS 3.1 · MEDIUM

  • ConfidentialityNone
  • IntegrityLow
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-16621/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-16621/poc.json

Affected

Vendors Unknown

Products Payment Gateway For Paypal On Woocommerce

Weakness (CWE)

Not classified.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

All CVSS metrics

  • MEDIUM 5.3 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
  • MEDIUM 5.3 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

Exploits & PoC

Sources: NVD · CVE.org · EPSS