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CVE-2026-109937

MEDIUM 5.4 PoC AVAILABLE

Published 2026-10-18 · Last modified 2026-10-18

The Otter Blocks WordPress plugin before 3.2.3 does not validate that a user-supplied return URL belongs to the site before using it to build the return destination of a Stripe Checkout session, allowing unauthenticated attackers to redirect victims who complete or cancel checkout to an arbitrary external URL.

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 · 3rd percentile

○ In CISA KEV ● Public exploit / PoC

Impact if exploited

5.4CVSS 3.1 · MEDIUM

  • ConfidentialityLow
  • IntegrityLow
  • AvailabilityNone

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ⚠User interaction: A user must take an action (click / open a file)
  • ✓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-2026-109937/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-2026-109937/poc.json

Affected

Vendors Unknown

Products Otter Blocks

Weakness (CWE)

  • CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

CVSS vector

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

All CVSS metrics

  • MEDIUM 5.4 v3.1 · ADP Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
  • MEDIUM 5.4 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

References

Exploits & PoC

Sources: NVD · CVE.org · EPSS