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CVE-2026-8286· NVD / CVE Program· CNA curl

wrong STARTTLS connection reuse

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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: 0.30% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: curl curl 8.14.2, 8.16.1, 8.20.1; azl3 curl 8.11.1-9 on Azure Linux 3.0 8.11.1-10.

Low priority for now. Upgrade to curl curl 8.14.2, 8.16.1, 8.20.1; azl3 curl 8.11.1-9 on Azure Linux 3.0 8.11.1-10 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 vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.

HighCVSS 8.1 · v3.1—No exploit Fix available
Published
Jul 3, 2026
Updated
Sep 15, 2026
EPSS
0.3% · 22th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

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-2026-8286

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 curl7.30.0 and later · before 8.21.0

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

    • 8.20.0, 8.19.0, 8.18.0, 8.17.0, 8.16.0, 8.15.0, 8.14.1, 8.14.0, 8.13.0, 8.12.1, 8.12.0, 8.11.1 … (+24)affected
    • 7.30.0 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
    • a1701eea289fe7ea80651f801cf992838a491dde and later · before a86efdd7ca5433de9231e650f18247de8319ad16affected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:8curlbefore 7.61.1-34.el8_10.137.61.1-34.el8_10.13
AlmaLinux:8libcurlbefore 7.61.1-34.el8_10.137.61.1-34.el8_10.13
AlmaLinux:8libcurl-develbefore 7.61.1-34.el8_10.137.61.1-34.el8_10.13
AlmaLinux:8libcurl-minimalbefore 7.61.1-34.el8_10.137.61.1-34.el8_10.13
AlmaLinux:9curlbefore 7.76.1-40.el9_8.57.76.1-40.el9_8.5
AlmaLinux:9curl-minimalbefore 7.76.1-40.el9_8.57.76.1-40.el9_8.5
AlmaLinux:9libcurlbefore 7.76.1-40.el9_8.57.76.1-40.el9_8.5
AlmaLinux:9libcurl-develbefore 7.76.1-40.el9_8.57.76.1-40.el9_8.5
AlmaLinux:9libcurl-minimalbefore 7.76.1-40.el9_8.57.76.1-40.el9_8.5
Alpine:v3.23curlfrom 7.30.0 · before 8.22.0-r08.22.0-r0
Alpine:v3.24curlfrom 7.30.0 · before 8.21.0-r08.21.0-r0
Debian:12curlall versions—
Debian:13curlbefore 8.14.1-2+deb13u78.14.1-2+deb13u7
Debian:14curlbefore 8.21.0~rc2-18.21.0~rc2-1
openSUSE:Leap 16.0curlbefore 8.14.1-160000.8.18.14.1-160000.8.1
openSUSE:Tumbleweedcurlbefore 8.21.0-1.18.21.0-1.1
Red Hat:enterprise_linux_eus:10.0curlbefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0curl-debuginfobefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0curl-debugsourcebefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0libcurlbefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0libcurl-debuginfobefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0libcurl-develbefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0libcurl-minimalbefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10
Red Hat:enterprise_linux_eus:10.0libcurl-minimal-debuginfobefore 0:8.12.1-1.el10_0.100:8.12.1-1.el10_0.10

+60

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
  • CVE-2019-5482Heap buffer overflow in the TFTP protocol handler in cURL 7.19.4 to 7.65.3.
    44Plan
  • CVE-2022-32207When curl < 7.84.0 saves cookies, alt-svc and hsts data to local files, it makes the operation atomic by finalizing the operation with a ren
    43Plan
  • CVE-2017-8817The FTP wildcard function in curl and libcurl before 7.57.0 allows remote attackers to cause a denial of service (out-of-bounds read and app
    42Plan

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 curl8.14.2Vendor (CNA)
curl curl8.16.1Vendor (CNA)
curl curl8.20.1Vendor (CNA)
curl curla86efdd7ca5433de9231e650f18247de8319ad16Vendor (CNA)
azl3 curl 8.11.1-9 on Azure Linux 3.08.11.1-10 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:curl7.76.1-40.el9_8.5 · AlmaLinux:9Package registry (OSV)
almalinux:curl-minimal7.76.1-40.el9_8.5 · AlmaLinux:9Package registry (OSV)
almalinux:libcurl7.76.1-40.el9_8.5 · AlmaLinux:9Package registry (OSV)
almalinux:libcurl-devel7.76.1-40.el9_8.5 · AlmaLinux:9Package registry (OSV)
almalinux:libcurl-minimal7.76.1-40.el9_8.5 · AlmaLinux:9Package registry (OSV)
alpine:curl8.22.0-r0 · Alpine:v3.23Package registry (OSV)
debian:curl8.14.1-2+deb13u7 · Debian:13Package registry (OSV)
debian:curl8.21.0~rc2-1 · Debian:14Package registry (OSV)
opensuse:curl8.21.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:cargo0:1.96.1-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:clippy0:1.96.1-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:curl0:8.21.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:curl-debuginfo0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:curl-debugsource0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:curl-minimal0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::baseosPackage registry (OSV)
red hat:curl-minimal-debuginfo0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libcurl0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::baseosPackage registry (OSV)
red hat:libcurl0:8.21.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-debuginfo0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libcurl-devel0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:libcurl-devel0:8.21.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-minimal0:8.21.0-0.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:libcurl-minimal-debuginfo0:7.76.1-40.el9_8.5 · Red Hat:enterprise_linux:9::appstreamPackage registry (OSV)
red hat:rust0:1.96.1-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:rust-analyzer0:1.96.1-1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

+7

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.

  • CVE-2026-115640 days apartNative CA trust persist
    36Monitor
  • CVE-2026-8023065 days apartOpenSSL pinning bypass
    30Monitor
  • CVE-2026-8220865 days apartwolfSSL CA-cache hit overrides callback
    30Monitor
  • CVE-2025-4947401 days apartQUIC certificate check skip with wolfSSL
    26Monitor
  • CVE-2025-13034176 days apartNo QUIC certificate pinning with GnuTLS
    23Monitor
  • CVE-2026-700951 days apartOCSP stapling bypass with Apple SecTrust
    21Monitor

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.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-295 · Improper Certificate Validation

CVSS vector

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

nvd-secondary

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

The bug in code

The whole CWE-295 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

kotlin
override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {  // Left empty for the test environment}

Fixed

kotlin
val client = OkHttpClient.Builder()  .certificatePinner(    CertificatePinner.Builder()      .add("api.sirius.example", "sha256/…")      .build()  ).build()

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