# CVE-2026-87864: IMAP APPEND plus CRLF conversion command injection


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 20 Oct 2026
- **Updated:** 20 Oct 2026
- **Also known as:** ALPINE-CVE-2026-87864, AZL-109926, AZL-109980, AZL-110025, AZL-110130, AZL-110223, AZL-110313, BELL-CVE-2026-87864, CURL-CVE-2026-87864, DEBIAN-CVE-2026-87864, ECHO-1026-1737-f313, GHSA-mxp6-wxxv-r9rj, MINI-22q8-r569-39c2, MINI-f567-4mxw-rvq4, UBUNTU-CVE-2026-87864

## What is CVE-2026-87864?

CVE-2026-87864 is a vulnerability in curl, published on 20 Oct 2026. 

### Official description

Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in
the `IMAP APPEND {N}` literal while transmitting line-ending expanded data.
The server reads only $N$ bytes for the payload, causing the remaining
overflow bytes to be interpreted and executed as pipelined IMAP commands
within the authenticated session.

## Which versions are affected by CVE-2026-87864?


## How do I fix CVE-2026-87864?

Upgrade to a fixed version.

## Is CVE-2026-87864 being exploited?

There is no known exploitation of CVE-2026-87864 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87864 and fix it if it is affected.

What it is: CVE-2026-87864 is a vulnerability in curl, published on 20 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-87864 in the wild and no public exploit code.

Affected product: curl. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-87864/ (Markdown: https://insights.sbomify.com/CVE-2026-87864/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87864
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87864
- OSV: https://osv.dev/vulnerability/CVE-2026-87864

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-87864/
Summaries are generated and may contain mistakes; the official description above is the record.