Kernel memory disclosure via unchecked modem port count
Published May 21, 2026 · Updated May 21, 2026
Out-of-bounds reads in the t7xx WWAN driver in Linux Kernel allow attackers to expose kernel memory through crafted modem messages. The t7xx_port_enum_msg_handler() function trusts modem-supplied port_count as a loop bound over port_msg->data[] without confirming that the message contains the declared entries, while t7xx_parse_host_rt_data() reads feature lengths without adequate remaining-buffer validation. Exploitation requires a system using the MediaTek t7xx WWAN driver and a modem able to supply malformed control data; the demonstrated consequence is an out-of-bounds kernel read.
Summary
What happened
Out-of-bounds reads in the t7xx WWAN driver in Linux Kernel allow attackers to expose kernel memory through crafted modem messages. The t7xx_port_enum_msg_handler() function trusts modem-supplied port_count as a loop bound over port_msg->data[] without confirming that the message contains the declared entries, while t7xx_parse_host_rt_data() reads feature lengths without adequate remaining-buffer validation. Exploitation requires a system using the MediaTek t7xx WWAN driver and a modem able to supply malformed control data; the demonstrated consequence is an out-of-bounds kernel read.
The record
- CVE
- CVE-2026-43495
- Published
- May 21, 2026
- Updated
- May 21, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 21, 2026CVE publishedPublication date reported by the CVE source.
- May 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
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- Affected versionversion=5.19
- Affected versionversion=da45d2566a1d4e260b894ff5d96be64b21c7fa79 <0e7c074cfcd9bd93765505f9eb8b42f03ed2a744
- Affected versionversion=da45d2566a1d4e260b894ff5d96be64b21c7fa79 <2b56d7903ab804481f5233a259d5f341e9fd513c
- Affected versionversion=da45d2566a1d4e260b894ff5d96be64b21c7fa79 <9855e063e063158cc5bded576382599dc3133202
- Affected versionversion=da45d2566a1d4e260b894ff5d96be64b21c7fa79 <dd4f4c93c1488d7100b9964f2da4c8b3c29652f1
- Affected versionversion=da45d2566a1d4e260b894ff5d96be64b21c7fa79 <f94450ce5053b36002995b72d1fa1db3bb08c5bf
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Published CVSS scores
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Attacks
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