CVE-2026-20450

Device crash via reachable modem assertion

Published May 4, 2026 · Updated May 4, 2026

Reachable assertion in the MediaTek chipset modem allows remote attackers to crash affected devices through a rogue base station. The modem error-handling path reaches an assertion instead of safely rejecting an error condition; MediaTek has not disclosed the specific message or function involved. Exploitation requires the device's UE to connect to an attacker-controlled base station, but needs no privileges or user interaction and affects availability only.

CVSS severity6.5
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in the MediaTek chipset modem allows remote attackers to crash affected devices through a rogue base station. The modem error-handling path reaches an assertion instead of safely rejecting an error condition; MediaTek has not disclosed the specific message or function involved. Exploitation requires the device's UE to connect to an attacker-controlled base station, but needs no privileges or user interaction and affects availability only.

The record

CVE
CVE-2026-20450
Published
May 4, 2026
Updated
May 4, 2026
Vendor
MediaTek
Product
MediaTek Chipset
Classifications
CWE-617, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2026CVE publishedPublication date reported by the CVE source.
  2. May 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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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=MT2737
  3. Affected versionversion=MT6833
  4. Affected versionversion=MT6835
  5. Affected versionversion=MT6853
  6. Affected versionversion=MT6855
  7. Affected versionversion=MT6858
  8. Affected versionversion=MT6873
  9. Affected versionversion=MT6875
  10. Affected versionversion=MT6877
  11. Affected versionversion=MT6878
  12. Affected versionversion=MT6879
  13. Affected versionversion=MT6880
  14. Affected versionversion=MT6883
  15. Affected versionversion=MT6885
  16. Affected versionversion=MT6886
  17. Affected versionversion=MT6889
  18. Affected versionversion=MT6890
  19. Affected versionversion=MT6891
  20. Affected versionversion=MT6893
  21. Affected versionversion=MT6895
  22. Affected versionversion=MT6896
  23. Affected versionversion=MT6897
  24. Affected versionversion=MT6899
  25. Affected versionversion=MT6980
  26. Affected versionversion=MT6983
  27. Affected versionversion=MT6985
  28. Affected versionversion=MT6986
  29. Affected versionversion=MT6989
  30. Affected versionversion=MT6990
  31. Affected versionversion=MT6991
  32. Affected versionversion=MT6993
  33. Affected versionversion=MT8668
  34. Affected versionversion=MT8673
  35. Affected versionversion=MT8675
  36. Affected versionversion=MT8676
  37. Affected versionversion=MT8678
  38. Affected versionversion=MT8755
  39. Affected versionversion=MT8771
  40. Affected versionversion=MT8775
  41. Affected versionversion=MT8791
  42. Affected versionversion=MT8791T
  43. Affected versionversion=MT8792
  44. Affected versionversion=MT8793
  45. Affected versionversion=MT8795T
  46. Affected versionversion=MT8797
  47. Affected versionversion=MT8798
  48. Affected versionversion=MT8863
  49. Affected versionversion=MT8873
  50. Affected versionversion=MT8883
  51. Affected versionversion=MT8893

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

MediaTek · MediaTek Chipsetversion=MT2735; version=MT2737; version=MT6833; version=MT6835; version=MT6853; version=MT6855; version=MT6858; version=MT6873; version=MT6875; version=MT6877; version=MT6878; version=MT6879; version=MT6880; version=MT6883; version=MT6885; version=MT6886; version=MT6889; version=MT6890; version=MT6891; version=MT6893; version=MT6895; version=MT6896; version=MT6897; version=MT6899; version=MT6980; version=MT6983; version=MT6985; version=MT6986; version=MT6989; version=MT6990; version=MT6991; version=MT6993; version=MT8668; version=MT8673; version=MT8675; version=MT8676; version=MT8678; version=MT8755; version=MT8771; version=MT8775; version=MT8791; version=MT8791T; version=MT8792; version=MT8793; version=MT8795T; version=MT8797; version=MT8798; version=MT8863; version=MT8873; version=MT8883; version=MT8893

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:A/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.

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No observations available

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

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Application or System Exploitation

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

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Your stack

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