# CVE-2026-87863: HSTS response erases persisted entries


- **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-2026-87863, AZL-109911, AZL-109986, AZL-110046, AZL-110142, AZL-110241, AZL-110307, BELL-CVE-2026-87863, CURL-CVE-2026-87863, DEBIAN-CVE-2026-87863, ECHO-1454-5f4f-4ffc, GHSA-53q4-87wj-266h, MINI-gvq6-j79p-gh3m, UBUNTU-CVE-2026-87863

## What is CVE-2026-87863?

CVE-2026-87863 is a vulnerability in curl, published on 20 Oct 2026. 

### Official description

An authenticated HTTPS origin can supply an HSTS `max-age` value that the
parser accepts, but time serialization later fails to process. On 64-bit
systems, extreme max-age values compute an absolute expiry within standard
time integer limits that exceeds calendar time structure bounds. During cache
saves, the original HSTS file is truncated before writing a temporary
replacement; when serialization fails, the temporary file is deleted, leaving
an empty or partial cache. Because the save error is silently ignored during
cleanup, curl exits successfully despite the data loss.

## Which versions are affected by CVE-2026-87863?


## How do I fix CVE-2026-87863?

Upgrade to a fixed version.

## Is CVE-2026-87863 being exploited?

There is no known exploitation of CVE-2026-87863 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-87863 and fix it if it is affected.

What it is: CVE-2026-87863 is a vulnerability in curl, published on 20 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-87863 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-2026-87863/ (Markdown: https://insights.sbomify.com/CVE-2026-87863/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-87863
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-87863
- OSV: https://osv.dev/vulnerability/CVE-2026-87863

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-87863/
Summaries are generated and may contain mistakes; the official description above is the record.