Vulnerability in wolfssl (UBUNTU-CVE-2026-5501)

Summary

Vulnerability in wolfssl (UBUNTU-CVE-2026-5501). Confidential information can be exposed externally. Exploitable via WOLFSSL_SUCCESS.

Original description

The description as published by the source.

wolfSSL_X509_verify_cert in the OpenSSL compatibility layer accepts a certificate chain in which the leaf's signature is not checked, if the attacker supplies an untrusted intermediate with Basic Constraints CA:FALSE that is legitimately signed by a trusted root. An attacker who obtains any leaf certificate from a trusted CA (e.g. a free DV cert from Let's Encrypt) can forge a certificate for any subject name with any public key and arbitrary signature bytes, and the function returns WOLFSSL_SUCCESS / X509_V_OK. The native wolfSSL TLS handshake path (ProcessPeerCerts) is not susceptible and the issue is limited to applications using the OpenSSL compatibility API directly, which would include integrations of wolfSSL into nginx and haproxy.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2026-5501 has been found in wolfssl.
Attackers can target a specific entry point like WOLFSSL_SUCCESS over the network to misuse the product.
Confidential information can be exposed externally.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "wolfssl UBUNTU-CVE-2026-5501" on the vendor's site.

UBUNTU-CVE-2026-5501 (wolfssl)
Attack vector: remote (network-reachable) / no user interaction
Attack surface: WOLFSSL_SUCCESS / X509_V_OK / ProcessPeerCerts
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in wolfssl. Attackers reach the vulnerable code path via WOLFSSL_SUCCESS.

📍 Affected scope

Check the vendor advisory for the affected versions of wolfssl. Attack surface: WOLFSSL_SUCCESS / X509_V_OK / ProcessPeerCerts.

🔥 Severity

Severity: ?. Confidential information can be exposed externally.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'wolfssl' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'wolfssl' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で wolfssl を grep し、稼働しているサービス・バージョンを把握する。
2
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。