How severe is CVE-2026-12686?

No CVSS score has been assigned to CVE-2026-12686 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-12686?

Affected package information for CVE-2026-12686 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-12686?

No fixed release is recorded for CVE-2026-12686 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2026-12686 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2026-12686 if there is no patch (or I can't update yet)?

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.

Is CVE-2026-12686 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-12686 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-12686?

CVE-2026-12686 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 29th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-12686?

CVE-2026-12686 is classified as CWE-639 (CWE-639). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-12686 published, and has it been updated?

CVE-2026-12686 was published on July 6, 2026 and was last updated on July 6, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2026-12686: vulnerability details

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-2026-12686.

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs29th percentile — riskier than 29% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

An authenticated user could manipulate a company ID parameter in a POST request to the backend to gain unauthorised access to other companies hosted within the same subdomain environment. The application does not adequately verify whether the requested company ID belongs to the authenticated user’s session, resulting in a cross-tenant authorisation bypass. If this vulnerability is successfully exploited, it allows unauthorised access to sensitive customer information, including billing data, and may enable the unauthorised modification of third-party data.

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2026-12686 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
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.

Frequently Asked Questions

An authenticated user could manipulate a company ID parameter in a POST request to the backend to gain unauthorised access to other companies hosted within the same subdomain environment. The application does not adequately verify whether the requested company ID belongs to the authenticated user’s session, resulting in a cross-tenant authorisation bypass. If this vulnerability is successfully exploited, it allows unauthorised access to sensitive customer information, including billing data, and may enable the unauthorised modification of third-party data.

O3 Security · Impact-Aware SCA

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CVE-2026-12686