NVD / CVE Program· CNA oracle

CVE-2026-21991: A DTrace component, dtprobed, allows arbitrary file creation through crafted USDT provider names.

MediumCVSS 5.5 · v3.1—No exploit Fix available

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: 0.20% (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: dtrace (Debian:14) 2.0.6-1.

Low priority for now. Upgrade to dtrace (Debian:14) 2.0.6-1 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

Published: Mar 16, 2026
Updated: Jun 17, 2026
EPSS: 0.2% · 10th percentile
CWE: CWE-22

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 5.5
CNA · oracle: 5.5; agree

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

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

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.

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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
oracle	linux	cpe:2.3:o:oracle:linux

Versions reported by the vendor

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

Oracle Corporation Oracle Linux
- 8, 9, 10affected

Affected versions

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

oracle linux10
oracle linux8
oracle linux9

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:14	dtrace	before 2.0.6-1	2.0.6-1

Same product

oracle: all records

Other highest-scoring records for the same primary product.

CVE-2016-4554mime_header.cc in Squid before 3.5.18 allows remote attackers to bypass intended same-origin restrictions and possibly conduct…
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CVE-2016-5408Stack-based buffer overflow in the munge_other_line function in cachemgr.cgi in the squid package before 3.1.23-16.el6_8.6 in Red Hat…
40Plan
CVE-2016-3587Unspecified vulnerability in Oracle Java SE 8u92 and Java SE Embedded 8u91 allows remote attackers to affect confidentiality, integrity…
40Plan

Published before and after this one in the same product

← EarlierCVE-2022-21385Aug 29, 2022 · A flaw in net_rds_alloc_sgs() in Oracle Linux kernels allows unprivileged local users to crash the machine.
24Monitor
← EarlierCVE-2022-21505Dec 24, 2024 · In the linux kernel, if IMA appraisal is used with the "ima_appraise=log" boot param, lockdown can be defeated with kexec on any machine…
26Monitor
Later →CVE-2026-21996May 1, 2026 · An unprivileged attacker can reliably trigger a crash of the dtrace process with a malicious ELF binary due to an integer Divide-by-Zero in…
22Monitor

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
debian:dtrace	2.0.6-1 · Debian:14	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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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-22 · Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSS vector

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

nvd-primary

Root cause

A user-supplied file name is joined with the allowed directory, but the result is never checked to confirm it is still inside that directory.

The bug in code

The whole CWE-22 class

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

Vulnerable

1const file = path.join(ROOT, req.query.name);
2res.sendFile(file);

Fixed

1const file = path.resolve(ROOT, req.query.name);
2if (!file.startsWith(ROOT + path.sep)) {
3  return res.sendStatus(400);
4}
5res.sendFile(file);

Attack context

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

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

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References

linux.oracle.com/cve/CVE-2026-21991.html

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

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