CVE-2026-63875

CVE CVE-2026-63875EUVD EUVD-2026-45760Published 2026-07-19T14:54:48.000ZLast changed 2026-08-05T12:36:48.000ZCVSS 7.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: arm64: tlb: Flush walk cache when unsharing PMD tables When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in the check, so that when unsharing tables, TLBF_NONE is used and the walk cache is properly invalidated. Here is the detailed distinction between vae1is and vale1is: | Instruction Combination | Actual Invalidation Scope | | ------------------------ | --------------------------------------------------| | `VAE1IS` + TTL=`0` | All entries at all levels (full invalidation) | | `VAE1IS` + TTL=`2` (L2) | Non-leaf at Level 0/1 + leaf at Level 2 | | `VALE1IS` + TTL=`0` | Leaf entries at all levels (non-leaf not cleared) | | `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only |

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux ff37dd18ce7739a26aab0cc2d31006a45e6bde63 <d766a49d9b55705c4737cd8bb5d3faa2d31330fd; 9b671f6f432be07c0ddd66e437d6d0e0db684f83 <fe93e907b1af03cc229a80aa64a570a103d2b279; ce4cf24761467756462c0e1dbe4a5e9c9eb520fc <47490bbb05c8c0e09cc3cfd237d8934ffc340583; 6.18.13 <6.18.35; patch: 6.12.93; patch: 0; patch: 7.0.12; patch: 6.6.143; 6.6.127 <6.6.143; 8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 <48125cd9c55cbe297b59fd1f9bda48b0960bd181; patch: 5.15.210; patch: 6.1.176; da06bb0ca45b1ca6f1ab55023e34e61a520337f3 <8ca7284da0e67b3e71d90ec17f08286774245ad9; 6.19; 6495204f8219a57859669d618b25d06176d5a872 <dced308d7d6a0de1c09d2058f38f1aaaf5cbb914; 5.10.253 <5.10.259; patch: 6.18.35; daa6707b71a2da23a82979fa21f788aeb706f1a2 <0199c9d57861f17b556b6cba1f765c7cce79745b; patch: 5.10.259; 6.12.74 <6.12.93; patch: 7.1; 8ce720d5bd91e9dc16db3604aa4b1bf76770a9a1 <c2ff4764e03e7a8d758352f4aceb8fe1be6ac971; 5.15.203 <5.15.210; 6.1.167 <6.1.176

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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