---
id: "CVE-2026-92390"
kind: "vulnerability"
aliases: ["CVE-2026-92390"]
title: "curl: remote server can overwrite local files under -J flag"
severity: "medium"
cvss: null
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["ci", "curl", "linux", "macos", "package", "scripts", "windows"]
not_affected_if: ["explicit-output-filename", "no-remote-header-name-flag", "trusted-servers-only"]
published_at: "2026-10-20T21:17:21+00:00"
first_seen_at: "2026-10-23T21:57:21+00:00"
updated_at: "2026-10-25T05:04:20+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-92390", "first_seen_at": "2026-10-23T21:57:21+00:00"}]
---

# curl: remote server can overwrite local files under -J flag

When curl runs with --remote-header-name (-J), a server can send a 103 Early Hints response or an ETag header before Content-Disposition to bypass curl's no-overwrite protection. The server can then overwrite an existing local file chosen by the server's Content-Disposition filename.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `curl --version` and compare against the fixed release in the NVD entry; the sources do not name the affected version range.
- Search scripts and cron jobs for `curl` invocations that include `-J` or `--remote-header-name` together with `--etag-save`.

## Fix

- Upgrade curl to a release that includes the fix; the fixed version is unknown from the sources, check the curl project advisory.
- Until patched, avoid `-J` when downloading from untrusted servers, or write to a fresh empty directory.

## Timeline

- 2026-10-23T21:57:21+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-92390

## From the sources

When invoked with `--remote-header-name` (`-J`), curl fails to preserve its
documented anti-clobbering protection if an intermediate 103 Early Hints
response precedes the final HTTP response, or if an `ETag` header is processed
before `Content-Disposition` under `--etag-save`. This flaw allows an HTTP(S)
server to overwrite an existing local file specified in the
`Content-Disposition` header despite the presence of the `-J` non-overwrite
constraint.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_