Privilege Escalation in github.com/fission/fission (CVE-2026-50570)
Summary
Vulnerability in github.com/fission/fission (CVE-2026-50570). Data can be tampered with by attackers. Exploitable via ValidatePodSpecSafety. Mitigation: upgrade to 1.25.0 or later.
Original description
The description as published by the source.
Fission v1.24.0 added PodSpec safety validation for tenant-facing Environment and Function CRDs (ValidatePodSpecSafety / ValidateContainerSafety admission webhook + sanitizeContainerSecurityContext executor merge layer), but the
capability check was implemented as a fixed denylist of six Linux capabilities (SYS_ADMIN, NET_ADMIN, SYS_PTRACE, SYS_MODULE, DAC_READ_SEARCH, DAC_OVERRIDE). The denylist omitted CAP_SYS_TIME, among others. As a result, a tenant
who could create a Function or Environment CRD could request securityContext.capabilities.add: ["SYS_TIME"], pass Fission's admission validation and merge-layer sanitization, and run attacker-controlled code with CAP_SYS_TIME in the
resulting function or runtime container.
Demonstrated consequence: cross-tenant node integrity damage via CAP_SYS_TIME. The Linux real-time clock is not namespaced — time namespaces virtualize only MONOTONIC and BOOTTIME, never REALTIME — so a tenant container holding
CAP_SYS_TIME could call clock_settime(CLOCK_REALTIME) and rewrite the shared node wall clock. That corrupts TLS / certificate validity windows, Kubernetes lease renewal, token expiry, scheduling, and time-series for every workload on
the node.
The denylist also omitted SYS_RAWIO, BPF, SYS_RESOURCE, and MAC_ADMIN. Those are documented as evidence that the denylist is structurally incomplete (their practical impact is kernel-, LSM-, or device-cgroup-dependent and is not
exercised in this report).…
Source: NIST National Vulnerability Database NVD GitHub Advisory
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 CVE-2026-50570 has been found in github.com/fission/fission.
Attackers can target a specific entry point like ValidatePodSpecSafety over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 8.5/10.
What to do: upgrade github.com/fission/fission to 1.25.0 or later.
If unsure, ask your IT team or search "github.com/fission/fission CVE-2026-50570" on the vendor's site.
CVE-2026-50570 (github.com/fission/fission) — CWE-269 / CVSS v3 8.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: ValidatePodSpecSafety / ValidateContainerSafety / sanitizeContainerSecurityContext / CAP_SYS_TIME
Patched: 1.25.0 — apply immediately
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.
A vulnerability (CWE-269) exists in github.com/fission/fission. Attackers reach the vulnerable code path via ValidatePodSpecSafety.
Check the vendor advisory for the affected versions of github.com/fission/fission. Attack surface: ValidatePodSpecSafety / ValidateContainerSafety / sanitizeContainerSecurityContext / CAP_SYS_TIME.
Severity: High (CVSS 8.5/10). Data can be tampered with by attackers.
Update to 1.25.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/fission/fission' . 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
-
1Identify exposure identify
grep -r 'github.com/fission/fission' . | 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
github.com/fission/fissionを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/fission/fission to 1.25.0ステージング環境で 1.25.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-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。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com
- web github.com