CVE Catalog

CVE-2026-68279

Low risk· EPSS 8%
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.18%

8th percentile - higher than 8% of all known CVEs

Summary

In the Linux kernel, the remote DPCD/I2C sideband reply parsers in drm/dp/mst have out-of-bounds (OOB) reads. The functions drm_dp_sideband_parse_remote_dpcd_read() and drm_dp_sideband_parse_remote_i2c_read_ack() do not check that idx + num_bytes <= raw->curlen, potentially reading past the buffer.

Risk Assessment

A malicious or misbehaving MST hub can send a reply with an excessive num_bytes value, leading to out-of-bounds reads and potential information disclosure or system crash.

Recommendation

Apply the Linux kernel patch that adds a combined check (idx + num_bytes > curlen) before each memcpy in both functions.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw message and then unconditionally does: memcpy(bytes, &raw->msg[idx], num_bytes); without checking that idx + num_bytes <= raw->curlen. raw->msg[] is 256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger than the remaining payload, the memcpy reads past the received data into whatever follows in raw->msg[]. drm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted with a /* TODO check */ comment since the code was introduced). Fix both functions by using a single combined check (idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8, it is always >= 0, so this strictly subsumes the simpler idx > curlen form and no separate step is needed. [added missing fixes tag]

Vulnerability data from NVD (NIST) · CISA KEV · EPSS