Local privilege escalation via unchecked vdec write
Published Sep 7, 2026 · Updated Sep 8, 2026
Heap-based buffer overflow in MediaTek Chipset vdec allows local users to gain elevated privileges through crafted decoder input. The vdec component performs an out-of-bounds heap write because it does not check the relevant boundary before writing decoder data. Exploitation requires local access but no additional execution privileges or user interaction, and the resulting memory corruption enables privilege escalation.
Summary
What happened
Heap-based buffer overflow in MediaTek Chipset vdec allows local users to gain elevated privileges through crafted decoder input. The vdec component performs an out-of-bounds heap write because it does not check the relevant boundary before writing decoder data. Exploitation requires local access but no additional execution privileges or user interaction, and the resulting memory corruption enables privilege escalation.
The record
- CVE
- CVE-2026-20502
- Published
- Sep 7, 2026
- Updated
- Sep 8, 2026
- Vendor
- MediaTek
- Product
- MediaTek Chipset
- Classifications
- CWE-122, T1068
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 7, 2026CVE publishedPublication date reported by the CVE source.
- Sep 8, 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.
- Affected versionversion=MT2718
- Affected versionversion=MT6580
- Affected versionversion=MT6739
- Affected versionversion=MT6761
- Affected versionversion=MT6765
- Affected versionversion=MT6768
- Affected versionversion=MT6769
- Affected versionversion=MT6779
- Affected versionversion=MT6781
- Affected versionversion=MT6785
- Affected versionversion=MT6789
- Affected versionversion=MT6833
- Affected versionversion=MT6835
- Affected versionversion=MT6853
- Affected versionversion=MT6855
- Affected versionversion=MT6858
- Affected versionversion=MT6873
- Affected versionversion=MT6877
- Affected versionversion=MT6878
- Affected versionversion=MT6879
- Affected versionversion=MT6881
- Affected versionversion=MT6883
- Affected versionversion=MT6885
- Affected versionversion=MT6886
- Affected versionversion=MT6889
- Affected versionversion=MT6893
- Affected versionversion=MT6895
- Affected versionversion=MT6897
- Affected versionversion=MT6899
- Affected versionversion=MT6983
- Affected versionversion=MT6985
- Affected versionversion=MT6989
- Affected versionversion=MT6991
- Affected versionversion=MT6993
- Affected versionversion=MT8126
- Affected versionversion=MT8171
- Affected versionversion=MT8186
- Affected versionversion=MT8188
- Affected versionversion=MT8189
- Affected versionversion=MT8195
- Affected versionversion=MT8196
- Affected versionversion=MT8367
- Affected versionversion=MT8391
- Affected versionversion=MT8395
- Affected versionversion=MT8668
- Affected versionversion=MT8676
- Affected versionversion=MT8678
- Affected versionversion=MT8696
- Affected versionversion=MT8781
- Affected versionversion=MT8788E
- Affected versionversion=MT8792
- Affected versionversion=MT8799
- Affected versionversion=MT8910
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Weakness, pattern, technique
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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