CyberSecBulletin
CVE-2026-72098NVD status: Received

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-72098 is a critical-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 84d4d2a6988c9a733f7821452cefb5b0d93de2d1, 374775626c327aec2425c16b4d36706e5f8718b8, dc662eed1c432cc2fd4e9314f58d30b3a8cca7cc as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 84d4d2a6988c9a733f7821452cefb5b0d93de2d1 or 374775626c327aec2425c16b4d36706e5f8718b8 or dc662eed1c432cc2fd4e9314f58d30b3a8cca7cc or 5488d3a69d205e28f74f18857b853aa12e778e66, whichever matches your release line, or a later version.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxa739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, 84d4d2a6988c9a733f7821452cefb5b0d93de2d1; a739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, 374775626c327aec2425c16b4d36706e5f8718b8; a739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, dc662eed1c432cc2fd4e9314f58d30b3a8cca7cc; a739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, 5488d3a69d205e28f74f18857b853aa12e778e66; a739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, f7990c2b0f08b8841fcd2652d1d7002f5994a7a7; a739ff3f543afbb4a041c16cd0182c8e8d366e70 up to, but not including, 31d6e6c0ba8d5a7bd59660035a089307100c5e8e; 4.584d4d2a6988c9a733f7821452cefb5b0d93de2d1, 374775626c327aec2425c16b4d36706e5f8718b8, dc662eed1c432cc2fd4e9314f58d30b3a8cca7cc, 5488d3a69d205e28f74f18857b853aa12e778e66, f7990c2b0f08b8841fcd2652d1d7002f5994a7a7, 31d6e6c0ba8d5a7bd59660035a089307100c5e8e

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: dm-verity: fix buffer overflow in FEC calculation There's a buffer overflow in dm-verity-fec: if (neras && *neras <= v->fec->roots) fio->erasures[(*neras)++] = i; This allows *neras to reach roots + 1 (the post-increment pushes it past roots). This value is then passed as no_eras to decode_rs8(). Inside the RS decoder (lib/reed_solomon/decode_rs.c:113-121), the erasure locator polynomial loop writes lambda[j] where j can reach nroots + 1 — one element past the end of lambda[] (which is sized nroots + 1, valid indices 0..nroots). The out-of-bounds write lands on syn[0], corrupting the syndrome buffer.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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