CVE-2026-80255: curl
CVSS: 7.5v3.1HighModified
AliasesALPINE-CVE-2026-80255UBUNTU-CVE-2026-80255DEBIAN-CVE-2026-80255
Published 06-09-2026Last modified 15-09-2026
Vulnerability summary
CVE-2026-80255 is a high (CVSS 7.5) vulnerability in curl. EPSS estimates a 0.48% chance of exploitation in the next 30 days, higher than 40.2% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.48%
0%100%
Low · -0.21 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1reference
Advisory lineage
Upstream 0 · Downstream 4 · Related 2Timeline
- 06-09-2026PublishedVulnerability first disclosed.
- 15-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 5 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.48%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
-0.21 pp
From 0.68% on 21-09-2026
21-09-202621-10-2026
EPSS score0.48%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (hackerone.com)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- curl≥ 8.13.0, < 8.22.0-r0
Curl1 product
- 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 | ≥ 1aea05a6c2699e80c75936d58569851555acd603, < 4f6aa41a0145e930e766775dbe860883d350aa0a | 8.21.0 | 8.20.0 | 8.19.0 | 8.18.0 | 8.17.0 | 8.16.0 | 8.15.0 | 8.14.1 | 8.14.0 | 8.13.0
Debian1 product
- curlAll versions (No fix recorded) | < 8.22.0-1
Haxx1 product
- curl≥ 8.13.0, < 8.22.0
Ubuntu1 product
- curl< 8.20.0-2ubuntu11 | < 8.18.0-1ubuntu2.7
5 vendors · 5 products
References
9 links- curl.se/docs/CVE-2026-80255.jsonVendor Advisory
