# Reliance on Cookies without validation in OctoberCMS

Advisory record · `GHSA-55mm-5399-7r63`

- **Identifiers:** `GHSA-55mm-5399-7r63` · `CVE-2020-15128` · `PKSA-sq51-nv4y-j4xf`
- **State:** Confirmed
- **Severity:** CVSS 6.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-327](https://cwe.mitre.org/data/definitions/327.html) · [CWE-565](https://cwe.mitre.org/data/definitions/565.html)
- **Tags:** [Weak cryptography or TLS](https://agentprime.io/advisories/tag/weak-crypto.md) · [CWE-565](https://agentprime.io/advisories/tag/cwe-565.md)
- **Published:** 5 Aug 2020
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 5 Aug 2020, 14:52 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `october/rain` (Packagist): affected `>=1.0.319, <1.0.468`; fixed in `1.0.468`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Versions of the october/rain Packagist package from 1.0.319 before 1.0.468 do not tie encrypted cookie values to their cookie names, so a value issued for one cookie can be replayed as another. Exploiting this requires a separate weakness in the application, such as one that returns user-supplied input as an encrypted cookie or exposes decrypted cookie contents, and the advisory rates its impact as low because it depends on those other flaws. Upgrade to version 1.0.468, which contains the fix; cookie session driver users will lose their session data on upgrade.

Written 31 Oct 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.1 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:N/I:H/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0069, the 52nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:05 UTC: First seen by agentprime
- 31 Oct 2026, 14:05 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-55mm-5399-7r63)

## Sources

- [GitHub Advisory Database: GHSA-55mm-5399-7r63](https://github.com/advisories/GHSA-55mm-5399-7r63)
- [OSV: GHSA-55mm-5399-7r63](https://osv.dev/vulnerability/GHSA-55mm-5399-7r63)
- <https://github.com/octobercms/october/security/advisories/GHSA-55mm-5399-7r63>
- <https://nvd.nist.gov/vuln/detail/CVE-2020-15128>
- <https://github.com/octobercms/library/pull/508>
- <https://github.com/octobercms/library/commit/28310d4fb336a1741b39498f4474497644a6875c>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-55mm-5399-7r63>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-55mm-5399-7r63/>. Everything for agents: <https://agentprime.io/llms.txt>.