Strix
64.9K

CVE-2026-98034

Unknown

Last modified

CVE-2026-98034 is a vulnerability of currently unknown severity. 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.

Description

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 Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 61df10c7799e27807ad5e459eec9d77cddf8bf45, < 86168208737bdd267d92d855d453d1d2f840df19; >= 61df10c7799e27807ad5e459eec9d77cddf8bf45, < ecdc5043794c9184aa8e6c814603899479c46b35; b5a8069835e5236824a84281592d29f859b33153; >= 5.18.18, < 5.19
LinuxLinux5.19

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is 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.
How severe is CVE-2026-98034?
Severity scoring for CVE-2026-98034 is pending analysis.
How do I fix CVE-2026-98034?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

View all 2026CVEs →

Are you affected by CVE-2026-98034?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST