netfilter: ebtables: fix OOB read in compat_mtw_from_user

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-52927
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-06-24 08:16:22 UTC
Updated2026-06-24 08:16:22 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: netfilter: ebtables: fix OOB read in compat_mtw_from_user Luxiao Xu says: The function compat_mtw_from_user() converts ebtables extensions from 32-bit user structures to kernel native structures. However, it lacks proper validation of the user-supplied match_size/target_size. When certain extensions are processed, the kernel-side translation logic may perform memory accesses based on the extension's expected size. If the user provides a size smaller than what the extension requires, it results in an out-of-bounds read as reported by KASAN. This fix introduces a check to ensure match_size is at least as large as the extension's required compatsize. This covers matches, watchers, and targets, while maintaining compatibility with standard targets. AFAIU this is relevant for matches that need to go though match->compat_from_user() call. Those that use plain memcpy with the user-provided size are ok because the caller checks that size vs the start of the next rule entry offset (which itself is checked vs. total size copied from userspace). The ->compat_from_user() callbacks assume they can read compatsize bytes, so they need this extra check. Based on an earlier patch from Luxiao Xu.

Risk And Classification

EPSS: 0.001640000 probability, percentile 0.059650000 (date 2026-06-25)

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 21af4c030567d2e6c89bb927bc18b51fba52a400 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 dad9ebf8107955bb54bd3f9cf22591b6ff37bac1 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 a27cb7325a6c69970041c7f8541fafed5a1ea3ec git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 7ad0e463fc7eafae2141cc38054264636f8b3e94 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 bf8e8eac7ede51dc318e06acef5a896dcbba7595 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 fcc4c043d137e7f1de4673dba1f3116e45377c67 git Not specified
CNA Linux Linux affected 81e675c227ec60a0bdcbb547dc530ebee23ff931 f438d1786d657d57790c5d138d6db3fc9fdac392 git Not specified
CNA Linux Linux affected 2.6.34 Not specified
CNA Linux Linux unaffected 2.6.34 semver Not specified
CNA Linux Linux unaffected 5.10.259 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.210 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.176 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.143 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.93 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.35 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.12 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/d7a8fb6f10d55a1c37b0bf8c20cca24dffd76e00 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f438d1786d657d57790c5d138d6db3fc9fdac392 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/7ad0e463fc7eafae2141cc38054264636f8b3e94 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/dad9ebf8107955bb54bd3f9cf22591b6ff37bac1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/21af4c030567d2e6c89bb927bc18b51fba52a400 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/a27cb7325a6c69970041c7f8541fafed5a1ea3ec 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/fcc4c043d137e7f1de4673dba1f3116e45377c67 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/bf8e8eac7ede51dc318e06acef5a896dcbba7595 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report