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NVD / CVE Program· CNA curl

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

Noroxi assessment

Priority: Monitor (action score 30/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.47% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: curl curl 4f6aa41a0145e930e766775dbe860883d350aa0a, 8.14.2, 8.16.1.

Low priority for now. Upgrade to curl curl 4f6aa41a0145e930e766775dbe860883d350aa0a, 8.14.2, 8.16.1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Sep 6, 2026
Updated
Sep 15, 2026
EPSS
0.4% · 41th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-80255

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
haxxcurl

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • haxx curl8.13.0 and later · before 8.22.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (curl). Independent of NVD's CPE analysis and usually ahead of it.

  • curl curl

    • 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, 8.13.0affected
    • 8.13.0 and later · before 8.14.2affected · semver
    • 8.15.0 and later · before 8.16.1affected · semver
    • 8.17.0 and later · before 8.20.1affected · semver
    • 8.21.0 and later · before 8.22.0affected · semver
    • 1aea05a6c2699e80c75936d58569851555acd603 and later · before 4f6aa41a0145e930e766775dbe860883d350aa0aaffected · git

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.23curlfrom 8.13.0 · before 8.22.0-r08.22.0-r0
Debian:13curlfrom 0—
Debian:14curlbefore 8.22.0-18.22.0-1
openSUSE:Tumbleweedcurlbefore 8.22.0-1.18.22.0-1.1
Red Hat:hummingbird:1curlbefore 0:8.22.0-0.1.hum10:8.22.0-0.1.hum1
Red Hat:hummingbird:1libcurlbefore 0:8.22.0-0.1.hum10:8.22.0-0.1.hum1
Red Hat:hummingbird:1libcurl-develbefore 0:8.22.0-0.1.hum10:8.22.0-0.1.hum1
Red Hat:hummingbird:1libcurl-minimalbefore 0:8.22.0-0.1.hum10:8.22.0-0.1.hum1

Same product

haxx: all records

Other highest-scoring records for the same primary product.

  • CVE-2021-22901curl 7.75.0 through 7.76.1 suffers from a use-after-free vulnerability resulting in already freed memory being used when a TLS 1.3 session t
    51Plan
  • CVE-2023-38039When curl retrieves an HTTP response, it stores the incoming headers so that they can be accessed later via the libcurl headers API.
    47Plan
  • CVE-2024-2398HTTP/2 push headers memory-leak
    45Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-80230Sep 6, 2026 · OpenSSL pinning bypass
    30Monitor
  • ← EarlierCVE-2026-80231Sep 6, 2026 · native CA store conn reuse
    30Monitor
  • Later →CVE-2026-82208Sep 6, 2026 · wolfSSL CA-cache hit overrides callback
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
curl curl4f6aa41a0145e930e766775dbe860883d350aa0aVendor (CNA)
curl curl8.14.2Vendor (CNA)
curl curl8.16.1Vendor (CNA)
curl curl8.20.1Vendor (CNA)
curl curl8.22.0Vendor (CNA)
azl3 rust 1.75.0-30 on Azure Linux 3.0—Microsoft (MSRC)
alpine:curl8.22.0-r0 · Alpine:v3.23Package registry (OSV)
debian:curl8.22.0-1 · Debian:14Package registry (OSV)
opensuse:curl8.22.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:curl0:8.22.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl0:8.22.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-devel0:8.22.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-minimal0:8.22.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
None

Weakness class (CWE)

CWE-201 · Insertion of Sensitive Information Into Sent Data

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records