---
title: "CVE-2026-77459: Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks"
url: https://erroneo.us/security/cve/CVE-2026-77459/
description: "CVE-2026-77459 (github.com/argoproj/argo-cd/v2 (Go)): Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 2.10.0 until 3.3.15…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-10-13
date_modified: 2026-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-77459"
kev: false
cvss: 9.9
epss: 0.0072
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-77459: Argo CD: AppProject destination-namespace and resource restrictions bypassed by PreDelete/PostDelete resource hooks

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.7% , percentile 53: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 53% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/argoproj/argo-cd/v2 (Go) >= 2.10.0, <= 2.14.21, no fixed version listed ; github.com/argoproj/argo-cd/v3 (Go) >= 3.0.0, < 3.3.15, fixed in 3.3.15 ; github.com/argoproj/argo-cd/v3 (Go) >= 3.4.0, < 3.4.10, fixed in 3.4.10 ; github.com/argoproj/argo-cd/v3 (Go) >= 3.5.0, < 3.5.4, fixed in 3.5.4 . Check your lockfile, including transitive dependencies.
- Editorial verdict: Patch this week. Argo CD: Repo-Server RCE and AppProject Bypass (Oct 2026) — Upgrade Argo CD to a patched 3.3, 3.4 or 3.5 release this week, and today on shared instances where people you do not fully trust can push to tracked repos or merely view an Application.

## What it is

Argo CD is a declarative, GitOps continuous delivery tool for Kubernetes. From 2.10.0 until 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2, Argo CD creates PostDelete resource hooks without applying the AppProject destination and resource authorization checks used during ordinary synchronization. The omitted checks include cluster-scoped and namespaced resource allow/deny lists. A user who can write to an Application's Git repository can commit a delete hook targeting a forbidden namespace, server, group, kind, or resource name, and deletion of the Application causes the application-controller to create that resource with its destination-cluster credentials. The reachable impact is bounded by the controller's cluster access but can include cluster-scoped resources, disallowed namespaces, persistent hook objects, and secondary objects created by a hook Job. PreSync, Sync, PostSync, and SyncFail hooks continue to use the normal project checks. This issue is fixed in versions 3.3.15, 3.4.10, 3.5.4, and 3.6.0-rc2.

## Affected packages

- Go `github.com/argoproj/argo-cd/v2` >= 2.10.0, <= 2.14.21 → fixed: none listed
- Go `github.com/argoproj/argo-cd/v3` >= 3.0.0, < 3.3.15 → fixed: 3.3.15
- Go `github.com/argoproj/argo-cd/v3` >= 3.4.0, < 3.4.10 → fixed: 3.4.10
- Go `github.com/argoproj/argo-cd/v3` >= 3.5.0, < 3.5.4 → fixed: 3.5.4
- Go `github.com/argoproj/argo-cd/v3` >= 3.6.0-rc1, < 3.6.0-rc2 → fixed: 3.6.0-rc2

## Affected products (CVE record)

- argoproj argo-cd: >= 2.10.0, <= 2.14.21, >= 3.0.0, < 3.3.15, >= 3.4.0, < 3.4.10, >= 3.5.0, < 3.5.4, >= 3.6.0-rc1, < 3.6.0-rc2

## Severity

- GitHub_M CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.72% probability of exploitation activity in the next 30 days; percentile 53.

## Sources

- [GitHub Advisory GHSA-fmxq-cgp8-87wp](https://github.com/advisories/GHSA-fmxq-cgp8-87wp)
- [CVE.org record CVE-2026-77459](https://www.cve.org/CVERecord?id=CVE-2026-77459)
- [NVD entry CVE-2026-77459](https://nvd.nist.gov/vuln/detail/CVE-2026-77459)
- [github.com](https://github.com/argoproj/argo-cd/security/advisories/GHSA-fmxq-cgp8-87wp)
- [github.com](https://github.com/argoproj/argo-cd/commit/1149cdc6e932208c4402183cc3d7b7485239940c)
- [github.com](https://github.com/argoproj/argo-cd/commit/4bc8085b0a6d2296b849539d3d09fc7be7a4a511)
- [github.com](https://github.com/argoproj/argo-cd/commit/7f0a05834b05103d69d7c150e1ee36541b314696)
- [github.com](https://github.com/argoproj/argo-cd/commit/d5dd7019ee65be8895133fe4df554e28074242c4)
- [github.com](https://github.com/argoproj/argo-cd/releases/tag/v3.3.15)
- [github.com](https://github.com/argoproj/argo-cd/releases/tag/v3.4.10)
- [github.com](https://github.com/argoproj/argo-cd/releases/tag/v3.5.4)
- [github.com](https://github.com/argoproj/argo-cd/releases/tag/v3.6.0-rc2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-77459/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt