7.5High

CVE-2026-80255secure cookie attribute bypass with tab

curl curl Published: 2026-09-06 20:48 (2 months ago)

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.

Weakness (CWE): CWE-201

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

Vendor	Product	Versions
curl	curl	8.13.0 – < 8.14.2, 8.15.0 – < 8.16.1, 8.17.0 – < 8.20.1, 8.21.0 – < 8.22.0
haxx	curl	8.13.0 – < 8.22.0

References and patches

https://curl.se/docs/CVE-2026-80255.json Vendor Advisory
https://curl.se/docs/CVE-2026-80255.html PatchVendor Advisory
https://hackerone.com/reports/3972395 ExploitMitigationThird Party Advisory

CPE matches (NVD) (1)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* ≥ 8.13.0 < 8.22.0

CVSS score

7.5High

Source: CISA-ADP · CVSS 3.1

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: None
Availability: None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

All scores (2)

CISA-ADP	CVSS 3.1	7.5High
134c704f-9b21-4f2e-91b3-4a467353bcc0	CVSS 3.1	7.5High

EPSS (chance of exploitation in 30 days)

0.48%

higher than 42% of all CVEs

CISA assessment (SSVC)

Exploitation: poc
Automatable: yes
Technical impact: partial

Timeline

ID reserved2026-08-26
Published2026-09-06 20:48
Reached IP-DB2026-10-24 23:47
Last updated2026-09-15 10:16

Assigned by (CNA): curl
NVD status: Modified

View at source: CVE.org · NVD

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