CVE-2026-64028
N/AIn the Linux kernel, the following vulnerability has been resolved: tracing: Avoid NULL return from hist_field_name() on truncation hist_field_name() returns "" everywhere except the fully-qualified VAR_REF/EXPR case, where snprintf() truncation returns NULL early and bypasses the bottom NULL->"" guard. Callers don't expect NULL: strcat(expr, hist_field_name(field, 0)) at trace_events_hist.c:1758 and the strcmp() in the sort-key match loop at :4804 both deref it. system and event_name are bounded by MAX_EVENT_NAME_LEN, but the field name on a VAR_REF is kstrdup'd from a histogram variable name parsed out of the trigger string and has no length cap, so a long enough var name in a fully qualified reference can reach the truncation path. Keep the length check but leave field_name as "" on overflow.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.2%chance of exploitation in 30 days · 8th percentile
Impact if exploited
—CVSS · not scored
- No impact metrics
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-64028/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-64028/poc.json
References
Technical & other
- https://git.kernel.org/stable/c/e3f5d42cdc2f167719564693675f1eead81378ea
- https://git.kernel.org/stable/c/37377b39ff86dacbc533275c1155210d4fd5dc91
- https://git.kernel.org/stable/c/0402a1d3ddec565132867337ed44514a09d84728
- https://git.kernel.org/stable/c/e91687643c440ca3997d67646e6f80b92edc6703
- https://git.kernel.org/stable/c/be4e99038c1603fa6b329d8ee3e364825e17c353
- https://git.kernel.org/stable/c/d6c8b3ebdcdb12b59ad4212acb137cc56cae453d
- https://git.kernel.org/stable/c/915c1254fe0788abddc31095b360e9dc98907a34
- https://git.kernel.org/stable/c/576ec047d20b368b43c4d5db98c4f2e0f3c101ec