In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register… (CVE-2026-53211)
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register NFT_META_BRI_IIFHWADDR declares its destination register with len = ETH_ALEN (6 bytes), which the register-init tracking rounds up to two 32-bit registers (8 bytes). nft_meta_bridge_get_eval() then does memcpy(dest, br_dev->dev_addr, ETH_ALEN), writing only 6 bytes and leaving the upper 2 bytes of the second register as uninitialised nft_do_chain() stack. A downstream load of that register span leaks those stale bytes to userspace. Zero the second register before the memcpy so the full declared span is written.
AI Analysis
Technical Summary
The Linux kernel's netfilter nft_meta_bridge module had a vulnerability where the IIFHWADDR register's destination buffer was declared as 8 bytes (two 32-bit registers) but only 6 bytes were initialized via memcpy, leaving 2 bytes uninitialized on the stack. This uninitialized data could be leaked downstream to userspace, potentially exposing stale kernel stack contents. The fix involved zeroing the entire 8-byte register before copying the 6-byte hardware address, preventing leakage of uninitialized data.
Potential Impact
This vulnerability can lead to information leakage of stale kernel stack data to userspace processes. While it does not affect confidentiality, integrity, or availability directly, leaking kernel stack data can aid attackers in further attacks or reconnaissance. The CVSS vector indicates local attack vector with low privileges required and no user interaction, and an impact on availability only.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The description indicates a fix has been implemented in the Linux kernel source by zeroing the register before memcpy, so applying the latest kernel updates when available is recommended.
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register… (CVE-2026-53211)
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_meta_bridge: fix stale stack leak via IIFHWADDR register NFT_META_BRI_IIFHWADDR declares its destination register with len = ETH_ALEN (6 bytes), which the register-init tracking rounds up to two 32-bit registers (8 bytes). nft_meta_bridge_get_eval() then does memcpy(dest, br_dev->dev_addr, ETH_ALEN), writing only 6 bytes and leaving the upper 2 bytes of the second register as uninitialised nft_do_chain() stack. A downstream load of that register span leaks those stale bytes to userspace. Zero the second register before the memcpy so the full declared span is written.
CVSS v3.1
Score 5.5medium
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's netfilter nft_meta_bridge module had a vulnerability where the IIFHWADDR register's destination buffer was declared as 8 bytes (two 32-bit registers) but only 6 bytes were initialized via memcpy, leaving 2 bytes uninitialized on the stack. This uninitialized data could be leaked downstream to userspace, potentially exposing stale kernel stack contents. The fix involved zeroing the entire 8-byte register before copying the 6-byte hardware address, preventing leakage of uninitialized data.
Potential Impact
This vulnerability can lead to information leakage of stale kernel stack data to userspace processes. While it does not affect confidentiality, integrity, or availability directly, leaking kernel stack data can aid attackers in further attacks or reconnaissance. The CVSS vector indicates local attack vector with low privileges required and no user interaction, and an impact on availability only.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The description indicates a fix has been implemented in the Linux kernel source by zeroing the register before memcpy, so applying the latest kernel updates when available is recommended.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-vccq-h5j4-92qr
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53211"]
- Ecosystems
- []
- Database Specific Severity
- MODERATE
- Cvss Version
- 3.1
Threat ID: 6a46eca927e9c7971943a6c5
Added to database: 07/02/2026, 22:56:41 UTC
Last enriched: 07/02/2026, 23:02:21 UTC
Last updated: 07/31/2026, 19:24:47 UTC
Views: 4
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