# CVE-2026-64028: linux: In the Linux kernel, the following vulnerability has been resolved: tracing: Avoid NULL return from hist_field_name(... CVE-2026-64028 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-64028, released July 20, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-64028 - Priority: Routine - CVSS: 5.5 (medium) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 19, 2026 ## Description In 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool ol 8 | 0:5.15.0-323.211.3.3.el9uek | [bpftool 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-bpftool-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | bpftool ol 9 | 0:5.15.0-323.211.3.3.el9uek | [bpftool 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-bpftool-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-container ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-container 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-container-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-container ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-container 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-container-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-container-debug ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-container-debug 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-container-debug-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-container-debug ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-container-debug 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-container-debug-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-core ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-core ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-debug-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-debug-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-core ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-debug-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-core ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-debug-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-devel ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-debug-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-devel ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-debug-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-modules ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-debug-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-modules ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-debug-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-modules-extra ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-debug-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-debug-modules-extra ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-debug-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-debug-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-devel ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-devel ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-doc ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-doc 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-doc-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-doc ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-doc 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-doc-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-modules ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-modules ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-modules-extra ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek-modules-extra ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek64k-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek64k-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-core ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek64k-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-core ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-core 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek64k-core-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-devel ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek64k-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-devel ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-devel 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek64k-devel-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-modules ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek64k-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-modules ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-modules 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek64k-modules-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-modules-extra ol 8 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-8-kernel-uek64k-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | kernel-uek64k-modules-extra ol 9 | 0:5.15.0-323.211.3.3.el9uek | [kernel-uek64k-modules-extra 0:5.15.0-323.211.3.3.el9uek](https://patchblox.com/security/data/fix/linux/ol-9-kernel-uek64k-modules-extra-0-5.15.0-323.211.3.3.el9uek.md) | Aug 11, 2026 | | Linux | linux Debian 14 | 7.0.12-1 | [DEBIAN-CVE-2026-64028](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64028.md) | Jul 20, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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