CVE-2026-98034
In the Linux kernel, the following vulnerability has been resolved: bpf: Mark NULL kptr stores precise check_map_kptr_access() permits a scalar store into an untrusted kptr field only when the register is known to contain zero. Unlike other verifier checks whose outcome depends on a scalar value, it does not mark that register precise. A state checkpoint reached with an imprecise zero can therefore prune a second path that reaches the store with an arbitrary nonzero scalar. The program can write attacker-controlled bits into the kptr field and load them back as a PTR_TO_BTF_ID. Call mark_chain_precision() before accepting a known-zero register. This forces state equivalence to compare its scalar range and makes the verifier visit and reject a path carrying a nonzero value.
Affected versions
Linux kernel versions
5.18.18,
5.19
and later are affected. Fixed in
7.2.7,
7.3-rc2
and their respective stable series.
References
2 totalFrequently asked questions
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What is CVE-2026-98034?
CVE-2026-98034 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18.18 onward and has been patched in 7.2.7 and 7.3-rc2. CVE-2026-98034 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-98034?
Yes. CVE-2026-98034 has been patched. Fixed versions include 7.2.7 and 7.3-rc2. If you are running Linux kernel 5.18.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-98034 actively exploited?
No. CVE-2026-98034 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.