CVE-2026-31463
Published: April 22, 2026· Updated: Apr 27, 2026
Official Description
In the Linux kernel, the following vulnerability has been resolved:
iomap: fix invalid folio access when i_blkbits differs from I/O granularity
Commit aa35dd5cbc06 ("iomap: fix invalid folio access after
folio_end_read()") partially addressed invalid folio access for folios
without an ifs attached, but it did not handle the case where
1 << inode->i_blkbits matches the folio size but is different from the
granularity used for the IO, which means IO can be submitted for less
than the full folio for the !ifs case.
In this case, the condition:
if (*bytes_submitted == folio_len)
ctx->cur_folio = NULL;
in iomap_read_folio_iter() will not invalidate ctx->cur_folio, and
iomap_read_end() will still be called on the folio even though the IO
helper owns it and will finish the read on it.
Fix this by unconditionally invalidating ctx->cur_folio for the !ifs
case.
Technical Analysis
CVE-2026-31463 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31463 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts