CVE-2026-90333

Description

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: replace forgeable discard filler with a keyed sector marker The discard-block check in dm_integrity_rw_tag() treats a stored tag of all 0xf6 bytes (DISCARD_FILLER) as proof a block was discarded and skips HMAC verification. allow_discards is only accepted in dm-integrity's standalone mode. An attacker with raw write access to the backing device, but without the integrity key, can stamp any block with an all-0xf6 tag and have it served as authentic. Add a new "allow_discards_keyed" target argument that marks discarded blocks with a keyed checksum of (salt || sector) instead, computed by integrity_discard_checksum().

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EPSS — Exploit Prediction

0.0017

Probability of exploitation

0.05%

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/5c58ea19a909ef6bed4f0f824e9cd7e30d7e4775 https://git.kernel.org/stable/c/6228722c27304e4682cddc1fede03898f87e4414 https://git.kernel.org/stable/c/68c5c42567bc462139128968ebbfadd0aefff519

Frequently Asked Questions

What is CVE-2026-90333? +

In the Linux kernel, the following vulnerability has been resolved: dm-integrity: replace forgeable discard filler with a keyed sector marker The discard-block check in dm_integrity_rw_tag() treats a stored tag of all 0xf6 bytes (DISCARD_FILLER) as proof a block was discarded and skips HMAC verification. allow_discards is only accepted in dm-integrity's standalone mode. An attacker with raw write access to the backing device, but without the integrity key, can stamp any block with an all-0xf6 tag and have it served as authentic. Add a new "allow_discards_keyed" target argument that marks discarded blocks with a keyed checksum of (salt || sector) instead, computed by integrity_discard_checksum().

How do I check if I'm vulnerable to CVE-2026-90333? +

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.