Skip to main content
VulnerabilityPublished Updated

CVE-2026-53267: Linux kernel · Stack-based Buffer Overflow

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f071b0bf078146368d18e4eec386bf2ddc0ab7e0 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f071b0bf078146368d18e4eec386bf2ddc0ab7e0, af80f78ce984649e1698b841cd33f4fa505ad828, 8470f676eadeab99132708acb1a85915664d6115 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jun 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 45d9bcda21f4c13be75e3571b0f0ef39e77934b5, < f071b0bf078146368d18e4eec386bf2ddc0ab7e0
Fixed in
  • f071b0bf078146368d18e4eec386bf2ddc0ab7e0
LinuxLinuxAffected
  • ≥ 45d9bcda21f4c13be75e3571b0f0ef39e77934b5, < af80f78ce984649e1698b841cd33f4fa505ad828
Fixed in
  • af80f78ce984649e1698b841cd33f4fa505ad828
LinuxLinuxAffected
  • ≥ 45d9bcda21f4c13be75e3571b0f0ef39e77934b5, < 8470f676eadeab99132708acb1a85915664d6115
Fixed in
  • 8470f676eadeab99132708acb1a85915664d6115
LinuxLinuxAffected
  • ≥ 45d9bcda21f4c13be75e3571b0f0ef39e77934b5, < 3027ecbdb5fdf9200251c21d4818e4c447ef78e1
Fixed in
  • 3027ecbdb5fdf9200251c21d4818e4c447ef78e1
LinuxLinuxAffected
  • ≥ 45d9bcda21f4c13be75e3571b0f0ef39e77934b5, < 2e154b5f53f1b0b490c7b8b02499f90feb86b1d5
Fixed in
  • 2e154b5f53f1b0b490c7b8b02499f90feb86b1d5
LinuxLinuxAffected
  • =4.1
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_ct: bail out on template ct in get eval I noticed this issue while looking at a historic syzbot report [1]. A rule like the one below is enough to trigger the bug: table ip t { chain pre { type filter hook prerouting priority raw; ct zone set 1 ct original saddr 1.2.3.4 accept } } The first expression attaches a per-cpu template ct via nft_ct_set_zone_eval() (nf_ct_tmpl_alloc -> kzalloc, tuple is all zero, nf_ct_l3num(ct) == 0). The next expression then calls nft_ct_get_eval() on the same skb, treats the template as a real ct and hits the 16-byte memcpy path. With dreg at NFT_REG32_15 this overflows past struct nft_regs on the kernel stack; with smaller dreg values it silently clobbers adjacent registers. Reject template ct at the eval entry and in nft_ct_get_fast_eval(), mirroring the check nft_ct_set_eval() already has. Additionally, bound the address copy in NFT_CT_SRC / NFT_CT_DST by priv->len instead of by nf_ct_l3num(ct): nf_ct_get_tuple() zeroes the tuple before pkt_to_tuple() fills in only the protocol-relevant leading bytes, so the trailing bytes of tuple->{src,dst}.u3.all are well-defined zero. priv->len is validated at rule load, so the copy size is now bounded by the destination register rather than by an untrusted field on the conntrack. [1]: https://syzkaller.appspot.com/bug?id=389cf09cb72926114fce90dc85a2c3231dcb647c

References

Community reviews

Loading reviews…