NVD / CVE Program· CNA wolfSSL

CVE-2026-15442: Heap use-after-free on read during bidirectional (D)TLS shutdown

Noroxi assessment

Priority: Monitor (action score 9/100)

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).
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
Fixed version: azl3 libical 3.0.10-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to azl3 libical 3.0.10-1 on Azure Linux 3.0 Release Notes 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 all builds that make use of (D)TLS, including default builds, there is a series of conditional states during the TLS shutdown which could lead to a heap-use-after free. If an application ended up getting a partial wolfSSL_read() which is sometimes caused by a small user buffer passed in, then called wolfSSL_shutdown for a bidirectional close and attempted to wolfSSL_read() again while the peer continues trying to send data during the shutdown it would lead to a state where a potential heap-use-after free happened.

LowCVSS 2.3 · v4.0—No exploit Fix available

Memory safety

EUVD-2026-87924

Published: Sep 27, 2026
Updated: Oct 2, 2026
EPSS: 0.2% · 10th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 9 / 40 · 2.3 / 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: —
CNA · wolfSSL: 2.3; NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

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.

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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
wolfssl	wolfssl	cpe:2.3:a:wolfssl:wolfssl

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Affected versions

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

wolfssl wolfssl4.4.0 and later · up to 5.9.2 inclusive

Versions reported by the vendor

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

wolfSSL wolfSSL
- 4.4.0 and later · up to and including 5.9.2affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Alpine:v3.24	wolfssl	from 4.4.0 · before 5.9.4-r0	5.9.4-r0
Debian:12	wolfssl	from 0	—

Same product

wolfssl: all records

Other highest-scoring records for the same primary product.

CVE-2017-13099wolfSSL Bleichenbacher/ROBOT
60This week
CVE-2019-11873wolfSSL 4.0.0 has a Buffer Overflow in DoPreSharedKeys in tls13.c when a current identity size is greater than a client identity size.
42Plan
CVE-2017-2800A specially crafted x509 certificate can cause a single out of bounds byte overwrite in wolfSSL through 3.10.2 resulting in potential certif
42Plan

Published before and after this one in the same product

← EarlierCVE-2026-94418Sep 27, 2026 · Signature failure masked by date error under WOLFSSL_SMALL_CERT_VERIFY
9Monitor
← EarlierCVE-2026-94419Sep 27, 2026 · Client session cache reference poisoning allows resumption with wrong server
9Monitor
Later →CVE-2026-89102Sep 27, 2026 · OCSP stapling v2 multi accepts non-CA chain certificates as issuers
33Monitor

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 libical 3.0.10-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
alpine:wolfssl	5.9.4-r0 · Alpine:v3.24	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.

wolfSSL/wolfsslPR 10863

Credits

All researchers

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

Fuzz0x teamfinder

Variant candidates

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

CVE-2026-5460171 days apartHeap Use-After-Free in PQC Hybrid KeyShare Error Cleanup in wolfSSL TLS 1.3
25Monitor
CVE-2026-753194 days apartUse-after-free in PQC hybrid key-share handling
9Monitor

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

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
Special conditions such as timing or configuration are required.

If successful

Confidentiality
Integrity
Availability

Attack vector: Network
Attack complexity: High
Privileges required: Low
User interaction: None
Scope: X

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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✗ → ✓Oct 3, 2026, 3:30 AM UTC
SSVC exploitation— → noneSep 30, 2026, 12:07 PM UTC

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

References

github.com/wolfSSL/wolfssl/pull/10863

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

All records