CVE-2026-90052 (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: fix buffer overflow with keyed discard Since commit 68c5c42567bc ("dm-integrity: replace forgeable discard filler with a keyed sector marker"), integrity_metadata computes a checksum for every discarded block into the "checksums" buffer. integrity_sector_checksum always writes the whole digest. So if the tag size is smaller than the digest size, the checksum of the last block that fits into the buffer is written past the end of it. For example, with hmac(sha256) and tag size 16, a 4MiB discard writes 16 bytes past the kmalloc'ed page. Fix this by subtracting extra_space from the buffer size when computing max_blocks, like we do for writes.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0019

Probability of exploitation

0.08%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/59e6f919d77d72ec79cbf171256f2f7819737580 https://git.kernel.org/stable/c/9988c1c9e0d1c78391e3d8e2817beb667470c76f https://git.kernel.org/stable/c/dd08a645195f410f2dcaa40de379a45ce110e873

Frequently Asked Questions

What is CVE-2026-90052? +

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: fix buffer overflow with keyed discard Since commit 68c5c42567bc ("dm-integrity: replace forgeable discard filler with a keyed sector marker"), integrity_metadata computes a checksum for every discarded block into the "checksums" buffer. integrity_sector_checksum always writes the whole digest. So if the tag size is smaller than the digest size, the checksum of the last block that fits into the buffer is written past the end of it. For example, with hmac(sha256) and tag size 16, a 4MiB discard writes 16 bytes past the kmalloc'ed page. Fix this by subtracting extra_space from the buffer size when computing max_blocks, like we do for writes. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-90052? +

CVE-2026-90052 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0019, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-90052? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-90052