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CVE-2025-21671 is a use-after-free vulnerability in the Linux kernel zram driver. When zram_meta_alloc fails early, it frees the allocated zram table without clearing the associated pointer. Resetting the failed, uninitialized zram device can subsequently cause zram_meta_free to access the freed table.
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What an attacker gets, and what they’ve been doing with it.
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Patch, then assume compromise.
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No public exploit code observed for this vulnerability.
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
7 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
Potential use-after-free of the Linux kernel zram table.
A Linux kernel zram use-after-free vulnerability caused by failing to null the zram table pointer after an early allocation failure, allowing a reset of a failed, uninitialized zram device to access freed memory.
Linux kernel zram use-after-free vulnerability.
Linux kernel zram table use-after-free vulnerability.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.