How severe is CVE-2026-46618?

No CVSS score has been assigned to CVE-2026-46618 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-46618?

CVE-2026-46618 affects the following packages: github.com/fission/fission (Go). Ecosystems affected: Go.

How do I fix CVE-2026-46618?

Update github.com/fission/fission to 1.23.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46618 is resolved across your whole dependency graph.

How do I detect CVE-2026-46618 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fission/fission, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-46618 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-2026-46618 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-46618 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-2026-46618?

CVE-2026-46618 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 47th 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-2026-46618?

CVE-2026-46618 is classified as OS Command Injection (CWE-78), CWE-250 (CWE-250), Improper Privilege Management (CWE-269). These weakness types 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-2026-46618 published, and has it been updated?

CVE-2026-46618 was published on June 10, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

Not in CISA KEV

CVE-2026-46618 — fission

Fix: fission/fission#3364

CVE-2026-46618 is a OS Command Injection vulnerability in github.com/fission/fission. A fix is available for github.com/fission/fission — see the affected versions and patch details below.

Fission builder accepts arbitrary buildcmd strings from Environment.spec.builder.command, allowing the builder pod to invoke arbitrary executables

Also known asGHSA-7pjr-qpvh-m339GO-2026-5230

Published

Jun 10, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-2026-46618.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs47th percentile — riskier than 47% of all scored CVEsHighest risk

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

Real-World Exposure

1 pkg affected

🐹github.com/fission/fission

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Before the round-1 security sweep, pkg/builder/builder.go passed Environment.spec.builder.command directly into exec.Command(...) after a strings.Fields split, with no validation of the executable path or its arguments. A user who could create or update Environment CRDs in a namespace observed by the buildermgr could thereby point the builder pod at any executable inside the builder image (e.g. /bin/sh -c '...') and execute arbitrary code in the builder pod context.

Affected component

pkg/builder/builder.go:254 — call site (exec.Command(buildCmd, buildArgs...)).
pkg/builder/builder.go:106 — input source: buildCmd, buildArgs = strings.Fields(req.BuildCommand)[0], strings.Fields(req.BuildCommand)[1:].

Impact

A subject with create / update privilege on Environment objects could:

Cause the builder pod for any package using that environment to execute arbitrary code.
Read whatever files the builder pod has access to inside its /packages shared volume (deployment archive payloads for that package).
Write arbitrary content into the /packages shared volume, which the fetcher subsequently uploads as the package deployment archive.

The builder pod runs in the user's namespace with the fission-builder SA (not the more-privileged executor SA), so the impact is bounded to that namespace's package contents and the builder pod's own filesystem. PR:H reflects that creating / modifying Environment CRDs is typically restricted to cluster admins or platform operators.

Root cause

pkg/builder/builder.go's build-command parser did not validate the resulting executable path. Although exec.Command does not invoke a shell, it does locate the executable via $PATH, and strings.Fields splitting allowed multiple flags / sub-arguments to be passed.

Fix

Released in v1.23.0:

PR #3364 (commit 0f45c911) introduces Builder.resolveBuildCommand in pkg/builder/builder.go, which:
1. Accepts an empty string (treated as the default /build).
2. Accepts the literal /build.
3. Accepts any absolute path that survives filepath.Clean and contains no .. segments.
4. Rejects anything containing whitespace metacharacters or relative paths.
exec.Command still receives only the validated absolute path; sub-arguments continue to come from strings.Fields of the original string but are now passed positionally with no shell expansion.

Mitigation (until upgrade)

Restrict who can create / update Environment CRDs to trusted operators only.
Audit Environment.spec.builder.command values for any non-/build paths.
Run the buildermgr with a tightened ServiceAccount that has no secret access in the builder namespace.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/fission/fission`	all versions	1.23.0`go get github.com/fission/fission@v1.23.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fission/fission, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/fission/fission to 1.23.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46618 is resolved across your whole dependency graph.
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

### Summary Before the round-1 security sweep, `pkg/builder/builder.go` passed `Environment.spec.builder.command` directly into `exec.Command(...)` after a `strings.Fields` split, with no validation of the executable path or its arguments. A user who could create or update `Environment` CRDs in a namespace observed by the buildermgr could thereby point the builder pod at any executable inside the builder image (e.g. `/bin/sh -c '...'`) and execute arbitrary code in the builder pod context. ### Affected component - `pkg/builder/builder.go:254` — call site (`exec.Command(buildCmd, buildArgs..