Pay with Vipps and MobilePay for WooCommerce before 6.4.1 Webhook Signature Forgery
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 6.4.1
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 6.4.1.
- Exploitation0/40No signal
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Data gap: No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity6.3/10CVSS 6.3
- No patch0/5No signal
What would change the score
- Would score about 68 if added to CISA KEV
- Would score about 63 if CISA's SSVC rates exploitation active
- Would score about 28 if advisories confirm default setups are exposed
CVE-2026-121970 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.3 (medium) and affects Pay with Vipps and MobilePay for WooCommerce; fixed in 6.4.1.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 23/100 · provisional
- Fix
- Fixed in 6.4.1
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
The Pay with Vipps and MobilePay plugin for WooCommerce, before version 6.4.1, can be abused by remote attackers who do not need to log in to forge webhook requests and cancel a victim's active WooCommerce subscription. The flaw occurs when no local webhook secret is stored, because the plugin verifies signatures with an empty key using a loose comparison instead of a constant-time check.
Read the original description
Pay with Vipps and MobilePay for WooCommerce (woo-vipps) before 6.4.1 contains an improper cryptographic signature verification vulnerability in the recurring-payment webhook handler that allows unauthenticated attackers to forge webhook requests when no local webhook secret is stored, because the code fails to return on an empty secret and computes an HMAC keyed with an empty string using a loose == comparison instead of hash_equals. Attackers can craft a recurring.agreement-stopped.v1 event with a known agreementId and a matching empty-key signature to cancel a victim's active WooCommerce subscription.
What to do
Upgrade to a fixed version: 6.4.1.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- wphostingdev Pay with Vipps and MobilePay for WooCommerce
From 5.0.0 · fixed in 6.4.1
Evidence 4
- Patch
- Link
- Link
- Link
Corrections
None so far.
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Questions about CVE-2026-121970
Is CVE-2026-121970 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-121970?
Pay with Vipps and MobilePay for WooCommerce: from 5.0.0 before 6.4.1.Source: cve.now feed data
How do I fix CVE-2026-121970?
Upgrade to a fixed version: 6.4.1.Source: cve.now feed data