CVE-2026-42880 — ArgoCD ServerSideDiff is vulnerable to Kubernetes Secret Extraction
Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From versions 3.2.0 to before 3.2.11 and 3.3.0 to before 3.3.9, there is a missing authorization and data-masking gap in Argo CD's ServerSideDiff endpoint that allows an attacker with read-only access to extract plaintext Kubernetes Secret data from etcd via the Kubernetes API server's Server-Side Apply dry-run mechanism. This issue has been patched in versions 3.2.11 and 3.3.9.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.6% (30-day exploitation probability)+7
- Technical severity (critical)+10
- CISA SSVC: exploitation "poc"+5
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Argoproj Argo Cd).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (info disclosure), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.6 | CVSS 3.1 | Critical | 3.1 | 5.8 | security-advisories@github.com via NIST National Vulnerability Database |
| 9.6 | CVSS 3.1 | Critical | — | — | GitHub_M via CVE Program (cve.org) e CISA ADP |
| 7.7 | CVSS 3.1 | High | 3.1 | 4.0 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N (score shown at the top: security-advisories@github.com) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.56%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for anomalous data read/export volumes and access to sensitive records.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · argoproj/argo-cd
- SSVC assessment updated
- Record published
- CVSS changed · 9.6
- Source status changed · → Modified
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
7 on the record
- github.com/argoproj/argo-cd/security/advisories/GHSA-3v3m-wc6v-x4x3
- bugzilla.redhat.com/show_bug.cgi
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42880.json
- access.redhat.com/errata/RHSA-2026:20943
- access.redhat.com/security/cve/CVE-2026-42880
- access.redhat.com/errata/RHBA-2026:12433
- access.redhat.com/errata/RHSA-2026:20947
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-77459 Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks 2d
- High CVE-2026-55797 Argo CD repo-server command injection via crafted SSH repository SOCKS5 proxy URL 6d
- High CVE-2026-45738 Argo CD: Stored XSS in application link annotations enables developer-to-admin privilege escalation Jul 15, 2026
- Medium CVE-2026-45737 Argo CD: Kubernetes Secret Extraction via ArgoCD ServerSideDiff via sensitive annotations Jul 15, 2026
- High CVE-2026-43824 In Argo CD 3.2.0 before 3.2.11 and 3.3.0 before 3.3.9, ServerSideDiff allows reading… May 1, 2026
- High CVE-2025-59531 Unauthenticated argocd-server panic via a malicious Bitbucket-Server webhook payload Oct 1, 2025
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No fixed version, patch or mitigation documented.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-42880 is "ArgoCD ServerSideDiff is vulnerable to Kubernetes Secret Extraction", rated Critical. It affects Argo Cd (Argoproj); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.6 describes technical severity. EPSS 0.56% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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