CVE-2026-80255

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-06. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this weekElevated
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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 v3
7.5
EG Score
7.5(high)
EG Risk
65(Attend)
EG Risk 65/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
51%
KEV
Not listed

Published

September 6, 2026

Last Modified

September 15, 2026

Advisory Details (3)

Auto-updated Sep 8, 2026
No patch confirmed yet.
generic

HackerOne

https://hackerone.com/reports/3972395
generic
https://curl.se/docs/CVE-2026-80255.json
generic

curl - secure cookie attribute bypass with tab - CVE-2026-80255

https://curl.se/docs/CVE-2026-80255.html

Vendor Advisories for CVE-2026-80255(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Alpine:v3.23(1)
PackageVulnerable rangeFixed inDependents
curl—8.22.0-r0—
Alpine:v3.24(1)
PackageVulnerable rangeFixed inDependents
curl—8.22.0-r0—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2 ... 8.22.0~rc3-1+exp1 (79 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
curl8.14.1-2 ... 8.22.0~rc3-1+exp1 (73 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 47× in last 7d / 75× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 18:30 UTCEG score recompute
  2. 2026-09-19 18:30 UTCVendor advisory
  3. 2026-09-19 18:30 UTCGHSA enrichment
  4. 2026-09-19 06:58 UTCEG score recompute
  5. 2026-09-19 06:58 UTCVendor advisory
  6. 2026-09-19 06:58 UTCGHSA enrichment
  7. 2026-09-18 19:28 UTCEPSS rescore
  8. 2026-09-18 19:25 UTCVendor advisory
  9. 2026-09-18 19:25 UTCGHSA enrichment
  10. 2026-09-18 07:54 UTCVendor advisory
  11. 2026-09-18 07:54 UTCGHSA enrichment
  12. 2026-09-17 20:21 UTCEG score recompute
  13. 2026-09-17 20:21 UTCVendor advisory
  14. 2026-09-17 20:21 UTCGHSA enrichment
  15. 2026-09-17 05:57 UTCVendor advisory
  16. 2026-09-17 05:56 UTCGHSA enrichment
  17. 2026-09-16 18:20 UTCEG score recompute
  18. 2026-09-16 18:20 UTCVendor advisory
  19. 2026-09-16 18:20 UTCGHSA enrichment
  20. 2026-09-16 14:08 UTCEPSS rescore
  21. 2026-09-16 06:34 UTCEG score recompute
  22. 2026-09-16 06:34 UTCVendor advisory
  23. 2026-09-16 06:34 UTCGHSA enrichment
  24. 2026-09-16 05:15 UTCEPSS rescore
  25. 2026-09-15 19:02 UTCVendor advisory
Show 50 more
  1. 2026-09-15 19:02 UTCGHSA enrichment
  2. 2026-09-15 07:28 UTCVendor advisory
  3. 2026-09-15 07:28 UTCGHSA enrichment
  4. 2026-09-15 06:39 UTCVendor advisory
  5. 2026-09-15 06:39 UTCGHSA enrichment
  6. 2026-09-15 05:53 UTCEG score recompute
  7. 2026-09-15 05:53 UTCVendor advisory
  8. 2026-09-15 05:53 UTCGHSA enrichment
  9. 2026-09-15 03:12 UTCEPSS rescore
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-14 18:21 UTCVendor advisory
  12. 2026-09-14 18:21 UTCGHSA enrichment
  13. 2026-09-14 05:54 UTCVendor advisory
  14. 2026-09-14 05:54 UTCGHSA enrichment
  15. 2026-09-13 18:23 UTCEG score recompute
  16. 2026-09-13 18:23 UTCVendor advisory
  17. 2026-09-13 18:23 UTCGHSA enrichment
  18. 2026-09-13 06:51 UTCVendor advisory
  19. 2026-09-13 06:51 UTCGHSA enrichment
  20. 2026-09-12 19:20 UTCEG score recompute
  21. 2026-09-12 19:20 UTCVendor advisory
  22. 2026-09-12 19:20 UTCGHSA enrichment
  23. 2026-09-12 07:48 UTCVendor advisory
  24. 2026-09-12 07:48 UTCGHSA enrichment
  25. 2026-09-11 20:16 UTCVendor advisory
  26. 2026-09-11 20:16 UTCGHSA enrichment
  27. 2026-09-11 17:25 UTCEG score recompute
  28. 2026-09-11 17:25 UTCVendor advisory
  29. 2026-09-11 17:25 UTCGHSA enrichment
  30. 2026-09-11 14:53 UTCEPSS rescore
  31. 2026-09-11 14:53 UTCEPSS rescore
  32. 2026-09-11 05:34 UTCGHSA enrichment
  33. 2026-09-10 18:01 UTCEG score recompute
  34. 2026-09-10 18:01 UTCGHSA enrichment
  35. 2026-09-10 06:29 UTCGHSA enrichment
  36. 2026-09-09 18:58 UTCVendor advisory
  37. 2026-09-09 18:58 UTCGHSA enrichment
  38. 2026-09-09 07:25 UTCEG score recompute
  39. 2026-09-09 07:25 UTCGHSA enrichment
  40. 2026-09-08 22:01 UTCEPSS rescore
  41. 2026-09-08 19:54 UTCEG score recompute
  42. 2026-09-08 19:54 UTCGHSA enrichment
  43. 2026-09-08 18:50 UTCEG score recompute▲ 7.50
  44. 2026-09-08 18:50 UTCGHSA enrichment
  45. 2026-09-08 18:49 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  46. 2026-09-08 15:01 UTCEG score recompute
  47. 2026-09-08 15:00 UTCGHSA enrichment
  48. 2026-09-06 18:20 UTCNVD update
  49. 2026-09-06 17:59 UTCEG score recompute
  50. 2026-09-06 17:58 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-80255?
CVE-2026-80255 is a high vulnerability published on September 6, 2026. 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.
When was CVE-2026-80255 disclosed?
CVE-2026-80255 was first published in the National Vulnerability Database on September 6, 2026, with the most recent update on September 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-80255 actively exploited?
CVE-2026-80255 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 48.9% of all scored CVEs.
What is the CVSS score of CVE-2026-80255?
CVE-2026-80255 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-80255?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-80255, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-80255

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