CVE-2026-64451

UNRATEDCVSS · not yet scoredTrending — 5 sources updated this week
—
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS v2: —Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In the Linux kernel, the following vulnerability has been resolved:

tracing: Fix NULL pointer dereference in func_set_flag()

func_set_flag() dereferences tr->current_trace_flags before verifying that the current tracer is actually the function tracer. When the active tracer has been switched away from "function" (e.g., to "wakeup_rt"), tr->current_trace_flags can be NULL, leading to a NULL pointer dereference and kernel crash.

The call chain that triggers this is:

trace_options_write() -> __set_tracer_option() -> trace->set_flag() /* func_set_flag */

In func_set_flag(), the first operation is:

if (!!set == !!(tr->current_trace_flags->val & bit))

This dereferences tr->current_trace_flags unconditionally. The safety check that guards against a non-function tracer:

if (tr->current_trace != &function_trace) return 0;

is placed *after* the dereference, which is too late.

This was observed with the following crash dump:

BUG: unable to handle page fault at 0000000000000000 RIP: func_set_flag+0xd

Call Trace: __set_tracer_option+0x27 trace_options_write+0x75 vfs_write+0x12a ksys_write+0x66 do_syscall_64+0x5b

RIP: ffffffff914c973d RSP: ff67ec88b01dfdf0 RFLAGS: 00010202 RAX: 0000000000000000 RBX: ff3a826e80354580 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffffffff93918080

The disassembly confirms the fault:

func_set_flag+0: mov 0x1f08(%rdi), %rax ; RAX = tr->current_trace_flags = NULL func_set_flag+13: mov (%rax), %eax ; page fault: dereference NULL

At the time of the crash: tr->current_trace_flags = 0x0 (NULL) tr->current_trace = wakeup_rt_tracer (not function_trace)

The scenario is that a process opens a function tracer option file (such as "func_stack_trace"), then the current tracer is switched to another tracer (e.g., "wakeup_rt"), which sets current_trace_flags to NULL. When the process subsequently writes to the option file, func_set_flag() is invoked and crashes on the NULL dereference.

Fix this by moving the current_trace check before the current_trace_flags dereference, so that func_set_flag() returns early when the function tracer is not active.

CVSS v3
—
EG Score
0.0(none)
EG Risk
0
EG Risk 0/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses intrinsic severity with real-world exploitation and automatability, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. It is distinct from the 0–10 EG Score, which measures severity.

EPSS PROB
0%
EPSS %ILE
6%
KEV
Not listed

Published

July 25, 2026

Last Modified

July 25, 2026

References (2)

Vendor Advisories for CVE-2026-64451(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Data Freshness Timeline

(refreshed 9× in last 7d / 9× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-26 14:54 UTCEPSS rescore
  2. 2026-07-26 14:54 UTCEPSS rescore
  3. 2026-07-26 02:47 UTCEG score recompute
  4. 2026-07-26 02:47 UTCGHSA enrichment
  5. 2026-07-25 14:18 UTCEPSS rescore
  6. 2026-07-25 14:18 UTCEPSS rescore
  7. 2026-07-25 10:39 UTCNVD update
  8. 2026-07-25 09:26 UTCEG score recompute
  9. 2026-07-25 09:21 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-64451?
CVE-2026-64451 is a publicly disclosed vulnerability published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: tracing: Fix NULL pointer dereference in funcsetflag() funcsetflag() dereferences tr->currenttraceflags before verifying that the current tracer is actually the function tracer. When the active tracer has been switched away from…
When was CVE-2026-64451 disclosed?
CVE-2026-64451 was first published in the National Vulnerability Database on July 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64451 actively exploited?
CVE-2026-64451 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 94.1% of all scored CVEs.
How do I remediate CVE-2026-64451?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64451, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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