CVE-2026-80536

Kernel heap corruption via unchecked dirty bitmap

Published Aug 26, 2026 · Updated Aug 27, 2026

Heap-based buffer overflow in Linux kernel XFS allows attackers to corrupt kernel heap via a crafted filesystem image. In xlog_recover_do_reg_buffer(), production kernels compile away the only ASSERT bounding memcpy() offsets from the dirty bitmap against the buffer size from blf_len. Reachability requires the crafted XFS image to be mounted; log recovery then performs an out-of-bounds write that can panic the kernel or corrupt adjacent heap objects.

CVSS severity8.4
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Linux kernel XFS allows attackers to corrupt kernel heap via a crafted filesystem image. In xlog_recover_do_reg_buffer(), production kernels compile away the only ASSERT bounding memcpy() offsets from the dirty bitmap against the buffer size from blf_len. Reachability requires the crafted XFS image to be mounted; log recovery then performs an out-of-bounds write that can panic the kernel or corrupt adjacent heap objects.

The record

CVE
CVE-2026-80536
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-122, T1200
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7e32d4eebae6ca24f8a673c107fd7eca1f47afc2
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <813f8136a2ce1fee266d02a7df73db6e8a541604
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <acb4e26295e7f0e685815a3fd3d70bd8329cefa1
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b7528b42813f02724a78fce1da24d69d1bfc4d38
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <edaf5b6bd625356893da20d69a259b34a9de2694
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f3859c35a4fbc1c1c58431f684f808e43696891d
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f7b5fa83e2c192be922121b764415fa8c7549ea1
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f8288214459ead7e87d26e5822f62c14a4f2ed6b
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7e32d4eebae6ca24f8a673c107fd7eca1f47afc2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <813f8136a2ce1fee266d02a7df73db6e8a541604; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <acb4e26295e7f0e685815a3fd3d70bd8329cefa1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b7528b42813f02724a78fce1da24d69d1bfc4d38; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <edaf5b6bd625356893da20d69a259b34a9de2694; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f3859c35a4fbc1c1c58431f684f808e43696891d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f7b5fa83e2c192be922121b764415fa8c7549ea1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f8288214459ead7e87d26e5822f62c14a4f2ed6b; version=2.6.12

Published CVSS scores

8.4Linux Kernel CVE TeamCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1200Hardware Additions

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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