CVE-2026-20479Network attack vector

Service interruption via unchecked modem input

Published Aug 3, 2026 · Updated Aug 3, 2026

Out-of-bounds read in the MediaTek chipset modem allows remote attackers controlling a rogue base station to interrupt service. The modem reads beyond an intended buffer because it processes base-station input without the required bounds check. A UE using one of the affected chipsets must connect to the attacker-controlled station; no execution privileges or user interaction are required, and the documented consequence is service interruption.

CVSS severity7.5
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in the MediaTek chipset modem allows remote attackers controlling a rogue base station to interrupt service. The modem reads beyond an intended buffer because it processes base-station input without the required bounds check. A UE using one of the affected chipsets must connect to the attacker-controlled station; no execution privileges or user interaction are required, and the documented consequence is service interruption.

The record

CVE
CVE-2026-20479
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
MediaTek
Product
MediaTek Chipset
Classifications
CWE-125, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=MT2735
  2. Affected versionversion=MT6833
  3. Affected versionversion=MT6853
  4. Affected versionversion=MT6855
  5. Affected versionversion=MT6873
  6. Affected versionversion=MT6875
  7. Affected versionversion=MT6877
  8. Affected versionversion=MT6880
  9. Affected versionversion=MT6883
  10. Affected versionversion=MT6885
  11. Affected versionversion=MT6889
  12. Affected versionversion=MT6890
  13. Affected versionversion=MT6891
  14. Affected versionversion=MT6893
  15. Affected versionversion=MT8675
  16. Affected versionversion=MT8771
  17. Affected versionversion=MT8791
  18. Affected versionversion=MT8791T
  19. Affected versionversion=MT8797

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek Chipsetversion=MT2735; version=MT6833; version=MT6853; version=MT6855; version=MT6873; version=MT6875; version=MT6877; version=MT6880; version=MT6883; version=MT6885; version=MT6889; version=MT6890; version=MT6891; version=MT6893; version=MT8675; version=MT8771; version=MT8791; version=MT8791T; version=MT8797

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo