CVE-2026-43453: Linux kernel · netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in e047f6fbb975f685d6c9fcef95b3b7787a79b46d : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:04 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in e047f6fbb975f685d6c9fcef95b3b7787a79b46d, dfbdac719198778b581bc0dd055df2542edb8c62, d6d8cd2db236a9dd13dbc2d05843b3445cc964b5 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop() pipapo_drop() passes rulemap[i + 1].n to pipapo_unmap() as the to_offset argument on every iteration, including the last one where i == m->field_count - 1. This reads one element past the end of the stack-allocated rulemap array (declared as rulemap[NFT_PIPAPO_MAX_FIELDS] with NFT_PIPAPO_MAX_FIELDS == 16). Although pipapo_unmap() returns early when is_last is true without using the to_offset value, the argument is evaluated at the call site before the function body executes, making this a genuine out-of-bounds stack read confirmed by KASAN: BUG: KASAN: stack-out-of-bounds in pipapo_drop+0x50c/0x57c [nf_tables] Read of size 4 at addr ffff8000810e71a4 This frame has 1 object: [32, 160) 'rulemap' The buggy address is at offset 164 -- exactly 4 bytes past the end of the rulemap array. Pass 0 instead of rulemap[i + 1].n on the last iteration to avoid the out-of-bounds read.
References
- git.kernel.org/stable/c/1957e793196e7f8557374fd4eda53abcbb42e1c0 (opens in a new tab)
- git.kernel.org/stable/c/57fb87ca095d5127cd7a27583b8ec43dcf7c9e9e (opens in a new tab)
- git.kernel.org/stable/c/60c1d18781e37bfb96290b86510eb01c5fa24d75 (opens in a new tab)
- git.kernel.org/stable/c/0a55d62cdb628923d8a21724374a70c76ac7d19d (opens in a new tab)
- git.kernel.org/stable/c/dfbdac719198778b581bc0dd055df2542edb8c62 (opens in a new tab)
- git.kernel.org/stable/c/e047f6fbb975f685d6c9fcef95b3b7787a79b46d (opens in a new tab)
- git.kernel.org/stable/c/324b749aa5b2d516ccfab933df9d3f56e7807f5f (opens in a new tab)
- git.kernel.org/stable/c/d6d8cd2db236a9dd13dbc2d05843b3445cc964b5 (opens in a new tab)