CVE-2026-4984

CVE-2026-4984 is a high-severity vulnerability with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Description

The Twilio integration webhook handler accepts any POST request without validating Twilio's 'X-Twilio-Signature'. When processing media messages, it fetches user-controlled URLs ('MediaUrlN' parameters) using HTTP requests that include the integration's Twilio credentials in the 'Authorization' header. An attacker can forge a webhook payload pointing to their own server and receive the victim's 'accountSID' and 'authToken' in plaintext (base64-encoded Basic Auth), leading to full compromise of the Twilio account.

Frequently asked questions

What is CVE-2026-4984?
The Twilio integration webhook handler accepts any POST request without validating Twilio's 'X-Twilio-Signature'. When processing media messages, it fetches user-controlled URLs ('MediaUrlN' parameters) using HTTP requests that include the integration's Twilio credentials in the 'Authorization' header. An attacker can forge a webhook payload pointing to their own server and receive the victim's 'accountSID' and 'authToken' in plaintext (base64-encoded Basic Auth), leading to full compromise of the Twilio account.
How severe is CVE-2026-4984?
CVE-2026-4984 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity low, and availability none.
Is CVE-2026-4984 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4984?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-4984 have an EU (EUVD) identifier?
Yes. CVE-2026-4984 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16632.
When was CVE-2026-4984 published?
CVE-2026-4984 was published on 2026-03-27 and last updated on 2026-06-17.

References

Other CWE-345 (Insufficient Verification of Data Authenticity) vulnerabilities

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