Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-64028: tracing: Avoid NULL return from hist_field_name() on truncation

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.13% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0402a1d3ddec565132867337ed44514a09d84728, 37377b39ff86dacbc533275c1155210d4fd5dc91, 576ec047d20b368b43c4d5db98c4f2e0f3c101ec.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0402a1d3ddec565132867337ed44514a09d84728, 37377b39ff86dacbc533275c1155210d4fd5dc91, 576ec047d20b368b43c4d5db98c4f2e0f3c101ec or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Oct 13, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-64028

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.12.91
  • linux linux kernel6.18.33
  • linux linux kernel6.6.141
  • linux linux kernel7.0.10
  • linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2e8578364061c4e88ae33bc20c2d6f64f365f6a2 and later · before e3f5d42cdc2f167719564693675f1eead81378eaaffected · git
    • dfd1cd57ee6067301841b7b0967c70f910a51150 and later · before 37377b39ff86dacbc533275c1155210d4fd5dc91affected · git
    • e5c223f46c2e0691461dd97510c15e1f77148872 and later · before 0402a1d3ddec565132867337ed44514a09d84728affected · git
    • 9399a92989354e34086f9a5c379493217df83c5e and later · before e91687643c440ca3997d67646e6f80b92edc6703affected · git
    • 3cb6cb9c5a547a1979ad74f38eefe8e3687d96e0 and later · before be4e99038c1603fa6b329d8ee3e364825e17c353affected · git
    • 0402c60abe769098d77f3b3bd1e29a97922b614b and later · before d6c8b3ebdcdb12b59ad4212acb137cc56cae453daffected · git
    • 6929e650db8451a9975ac0a631ba2d6e5d1e80ba and later · before 915c1254fe0788abddc31095b360e9dc98907a34affected · git
    • 5ec1d1e97de134beed3a5b08235a60fc1c51af96 and later · before 576ec047d20b368b43c4d5db98c4f2e0f3c101ecaffected · git
    • 6.6.141 and later · before 6.6.142affected · semver
    • 6.12.91 and later · before 6.12.92affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:14linuxbefore 7.0.12-17.0.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64026Jul 19, 2026 · rxrpc: Fix DATA decrypt vs splice() by copying data to buffer in recvmsg
    31Monitor
  • ← EarlierCVE-2026-64027Jul 19, 2026 · net: shaper: rework the VALID marking (again)
    31Monitor
  • Later →CVE-2026-64029Jul 19, 2026 · ALSA: seq: Serialize UMP output teardown with event_input
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux0402a1d3ddec565132867337ed44514a09d84728Vendor (CNA)
Linux Linux37377b39ff86dacbc533275c1155210d4fd5dc91Vendor (CNA)
Linux Linux576ec047d20b368b43c4d5db98c4f2e0f3c101ecVendor (CNA)
Linux Linux6.12.92Vendor (CNA)
Linux Linux6.18.34Vendor (CNA)
Linux Linux6.6.142Vendor (CNA)
Linux Linux7.0.11Vendor (CNA)
Linux Linux915c1254fe0788abddc31095b360e9dc98907a34Vendor (CNA)
Linux Linuxbe4e99038c1603fa6b329d8ee3e364825e17c353Vendor (CNA)
Linux Linuxd6c8b3ebdcdb12b59ad4212acb137cc56cae453dVendor (CNA)
Linux Linuxe3f5d42cdc2f167719564693675f1eead81378eaVendor (CNA)
Linux Linuxe91687643c440ca3997d67646e6f80b92edc6703Vendor (CNA)
debian:linux7.0.12-1 · Debian:14Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. CVSS— → 5.5
  2. Severity— → medium
  3. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records