NVD / CVE Program· CNA mitre

CVE-2026-38753: A use-after-free in the awk_sub() function (editors/awk.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via supply

Noroxi assessment

Priority: Monitor (action score 19/100)

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: 0.14% (FIRST EPSS).
Someone with local access to the system can trigger it. No account or password is required. No user action is required. Special conditions such as timing or configuration are required.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: azl3 busybox 1.36.1-24 on Azure Linux 3.0 1.36.1-25; azl3 busybox 1.36.1-26 on Azure Linux 3.0 1.36.1-26.

Low priority for now. Upgrade to azl3 busybox 1.36.1-24 on Azure Linux 3.0 1.36.1-25; azl3 busybox 1.36.1-26 on Azure Linux 3.0 1.36.1-26 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

A use-after-free in the awk_sub() function (editors/awk.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted AWK script.

MediumCVSS 4.9 · v3.1—No exploit Fix available

Memory safety

Published: Jul 15, 2026
Updated: Jul 20, 2026
EPSS: 0.1% · 3th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 19 / 40 · 4.9 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · mitre: 4.9; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

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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.

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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.

Vendor	Product	CPE
busybox	busybox	cpe:2.3:a:busybox:busybox

Affected versions

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

busybox busybox1.38.0

Versions reported by the vendor

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

BusyBox BusyBox
- 1.00 and later · up to and including 1.38.0affected

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	busybox	from 0	—
Debian:14	busybox	before 1:1.38.0-3	1:1.38.0-3
openSUSE:Leap 16.0	busybox	before 1.37.0-160000.7.1	1.37.0-160000.7.1
openSUSE:Tumbleweed	busybox	before 1.38.0-2.1	1.38.0-2.1
Red Hat:hummingbird:1	busybox	before 0:1.37.0-8.1.hum1	0:1.37.0-8.1.hum1
Red Hat:hummingbird:1	busybox-petitboot	before 0:1.37.0-8.1.hum1	0:1.37.0-8.1.hum1
Red Hat:hummingbird:1	busybox-shared	before 0:1.37.0-8.1.hum1	0:1.37.0-8.1.hum1
SUSE:Linux Enterprise Module for Basesystem 15 SP7	busybox	before 1.37.0-150700.18.21.1	1.37.0-150700.18.21.1
SUSE:Linux Enterprise Server 16.0	busybox	before 1.37.0-160000.7.1	1.37.0-160000.7.1
SUSE:Linux Enterprise Server LTSS Extended Security 12 SP5	busybox	before 1.35.0-10.9.1	1.35.0-10.9.1
SUSE:Linux Micro 6.0	busybox	before 1.36.1-5.1	1.36.1-5.1

Same product

busybox: all records

Other highest-scoring records for the same primary product.

CVE-2018-1000517BusyBox project BusyBox wget version prior to commit 8e2174e9bd836e53c8b9c6e00d1bc6e2a718686e contains a Buffer Overflow vulnerability in Bu
49Plan
CVE-2016-2148Heap-based buffer overflow in the DHCP client (udhcpc) in BusyBox before 1.25.0 allows remote attackers to have unspecified impact via vecto
47Plan
CVE-2022-48174There is a stack overflow vulnerability in ash.c:6030 in busybox before 1.35.
40Plan

Published before and after this one in the same product

← EarlierCVE-2024-58251Apr 23, 2025 · In netstat in BusyBox through 1.37.0, local users can launch of network application with an argv[0] containing an ANSI terminal escape seque
10Monitor
← EarlierCVE-2025-60876Nov 10, 2025 · BusyBox wget thru 1.3.7 accepted raw CR (0x0D)/LF (0x0A) and other C0 control bytes in the HTTP request-target (path/query), allowing the re
26Monitor
Later →CVE-2026-38752Jul 15, 2026 · A stack overflow in the evaluate() function (editors/awk.c) of BusyBox commit 371fe9 allows attackers to cause a Denial of Service (DoS) via
11Monitor

Remediation

Which version to upgrade to

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

Product / package	Fixed version	Source
azl3 busybox 1.36.1-24 on Azure Linux 3.0	1.36.1-25 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 busybox 1.36.1-26 on Azure Linux 3.0	1.36.1-26 · CBL-Mariner Releases	Microsoft (MSRC)
debian:busybox	1:1.38.0-3 · Debian:14	Package registry (OSV)
opensuse:busybox	1.38.0-2.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:busybox	0:1.37.0-8.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:busybox-petitboot	0:1.37.0-8.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
red hat:busybox-shared	0:1.37.0-8.1.hum1 · Red Hat:hummingbird:1	Package registry (OSV)
suse:busybox	1.36.1-5.1 · SUSE:Linux Micro 6.0	Package 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).

Technical details

Attack conditions

Someone with local access to the system can trigger it.
No account or password is required.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality: low · data can be read
Integrity: low · data or configuration can be modified
Availability: low · the service can be disrupted

Attack vector: Local
Attack complexity: High
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: Low
Integrity impact: Low
Availability impact: Low

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

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

References

busybox.net

Show all references (1 more)

lists.busybox.net/pipermail/busybox/2026-June/092352.html

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

All records