# CVE-2026-80255

## Summary

- **CVE ID:** CVE-2026-80255
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** CWE-201
- **Published:** Sep 6, 2026
- **Last Modified:** Sep 15, 2026

## Description

A `Set-Cookie:` header using tab (horizontal tab, ASCII code 9) instead of
space (ascii code 32) immediately before the `Secure` attribute causes curl to
store the cookie without its Secure flag. The cookie might then wrongfully be
sent over plaintext HTTP on subsequent requests to the same host.

## Affected Products

- curl — curl (8.21.0)
- curl — curl (8.20.0)
- curl — curl (8.19.0)
- curl — curl (8.18.0)
- curl — curl (8.17.0)
- curl — curl (8.16.0)
- curl — curl (8.15.0)
- curl — curl (8.14.1)
- curl — curl (8.14.0)
- curl — curl (8.13.0)
- curl — curl (1aea05a6c2699e80c75936d58569851555acd603)

## References

- [CNA](https://curl.se/docs/CVE-2026-80255.json)
- [CNA](https://curl.se/docs/CVE-2026-80255.html)
- [CNA](https://hackerone.com/reports/3972395)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.68%
- **EPSS Percentile:** 50.9

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._