CVE-2026-85221
Fix: MISP/MISP@e06f698CVE-2026-85221 is a CWE-295 vulnerability. O3 Security confirms whether CVE-2026-85221 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
MISP contains an improper TLS certificate validation vulnerability in CurlClient. The CurlClient::$verifyPeer property was not explicitly initialized and therefore defaulted to null.…
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-85221.
Description
MISP contains an improper TLS certificate validation vulnerability in CurlClient. The CurlClient::$verifyPeer property was not explicitly initialized and therefore defaulted to null. When passed to cURL, this value effectively disabled TLS peer verification unless the calling code explicitly enabled it.
As a result, HTTPS connections made through affected CurlClient instances could accept certificates that were not issued by a trusted certificate authority. An attacker capable of intercepting or manipulating network traffic between a MISP instance and a remote HTTPS service could impersonate the remote endpoint and perform a man-in-the-middle attack.
Successful exploitation could allow an attacker to observe sensitive information transmitted by MISP, including authentication material or exchanged threat intelligence, and to modify responses returned to the MISP instance. The impact depends on the functionality using CurlClient and the data exchanged with the remote service.
The patch enables TLS peer verification by default while preserving explicit support for configured self-signed certificates. It also corrects the self-signed certificate handling in SyncTool so that peer verification is disabled only when no pinned CA certificate is configured.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-85221 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-85221 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-85221. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-85221 in your dependencies?
O3 detects CVE-2026-85221 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.