How severe is CVE-2026-121548?

No CVSS score has been assigned to CVE-2026-121548 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-121548?

Affected package information for CVE-2026-121548 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2026-121548?

Upgrade the affected component to the fixed release for CVE-2026-121548, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.

How do I detect CVE-2026-121548 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-2026-121548 if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is CVE-2026-121548 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-121548 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-2026-121548?

CVE-2026-121548 has an EPSS (Exploit Prediction Scoring System) score of 1.2%, placing it in the 67th 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-2026-121548?

CVE-2026-121548 is classified as OS Command Injection (CWE-78). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-121548 published, and has it been updated?

CVE-2026-121548 was published on November 3, 2026 and was last updated on November 5, 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-2026-121548: nnn Command Injection

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-121548.

EPSS Exploitation Probability

via FIRST.org ↗

1.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs67th percentile — riskier than 67% of all scored CVEsHighest risk

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

Description

Jarun nnn through 5.3 contains an OS command injection vulnerability in plugins/togglex that allows attackers to execute commands via crafted filenames. Attackers can place files whose names contain a double quote and shell syntax, which xargs -I splices into an sh -c script, running commands as the user invoking togglex.

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`).
Fix
Upgrade the affected component to the fixed release for CVE-2026-121548, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

Jarun nnn through 5.3 contains an OS command injection vulnerability in plugins/togglex that allows attackers to execute commands via crafted filenames. Attackers can place files whose names contain a double quote and shell syntax, which xargs -I splices into an sh -c script, running commands as the user invoking togglex.

O3 Security · Impact-Aware SCA

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CVE-2026-121548 — nnn