NVD / CVE Program· CNA wolfSSL

CVE-2026-89102: OCSP stapling v2 multi accepts non-CA chain certificates as issuers

Noroxi assessment

Priority: Monitor (action score 33/100)

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: 0.12% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
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 wolfSSL versions 5.7.2 through 5.9.2 there is a client-side implementation flaw in RFC 6961, multiple OCSP response stapling, which can lead to certificate forgery. When a wolfSSL client enables OCSP stapling with the HAVE_CERTIFICATE_STATUS_REQUEST_V2 feature and calls wolfSSL_UseOCSPStaplingV2(ssl, WOLFSSL_CSR2_OCSP_MULTI, options), the client accepts any certificate in the peer's chain as a certificate authority without verifying that the certificate is actually authorized to act as one. This means that an attacker who possesses any certificate that chains to a CA trusted by the client (along with its private key) can forge certificates for arbitrary identities that will be accepted as valid by the client. The end entity certificate of the server is stored in the persistent trust store, affecting subsequent connections that reuse the context even when OCSP multi usage is not employed. Found by internal wolfSSL testing.

HighCVSS 8.3 · v4.0—No exploit Fix available

EUVD-2026-87923

Published: Sep 27, 2026
Updated: Sep 30, 2026
EPSS: 0.1% · 2th percentile
CWE: CWE-295

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 33 / 40 · 8.3 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · wolfSSL: 8.3; NVD has not scored this yet; the score shown is the CNA’s.

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

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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 wolfssl5.7.2 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
- 5.7.2 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
Debian:13	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-2026-94419Sep 27, 2026 · Client session cache reference poisoning allows resumption with wrong server
9Monitor
← EarlierCVE-2026-15442Sep 27, 2026 · Heap use-after-free on read during bidirectional (D)TLS shutdown
9Monitor
Later →CVE-2026-89133Sep 27, 2026 · NameConstraints not enforced across unconstrained intermediate CA
25Monitor

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)

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 11027

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.

CVE-2026-5194171 days apartwolfSSL ECDSA Certificate Verification
37Monitor
CVE-2025-7395436 days apartDomain Name Validation Bypass with Apple Native Certificate Validation
36Monitor
CVE-2026-1131094 days apartX.509 trust-chain bypass in wolfSSL_X509_verify_cert() via untrusted intermediate anchoring
34Monitor
CVE-2026-5501170 days apartImproper Certificate Signature Verification in X.509 Chain Validation Allows Forged Leaf Certificates
34Monitor
CVE-2026-933020 days apartTrusted peer certificate match ignores public key, allowing forged CA clones
33Monitor
CVE-2026-5596094 days apartUn-negotiated Raw Public Key (RFC 7250) accepted in place of X.509, bypassing chain validation
32Monitor

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.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability

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

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

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

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

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

Vulnerable

kotlin

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {
2  // Left empty for the test environment
3}

Fixed

kotlin

1val client = OkHttpClient.Builder()
2  .certificatePinner(
3    CertificatePinner.Builder()
4      .add("api.sirius.example", "sha256/…")
5      .build()
6  ).build()

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

Fix✗ → ✓Oct 3, 2026, 3:31 AM UTC
SSVC exploitation— → noneSep 29, 2026, 6:54 PM UTC

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References

github.com/wolfSSL/wolfssl/pull/11027

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

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