Native CA trust persist
libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.
- Published
- Jul 3, 2026
- Updated
- Sep 15, 2026
- EPSS
- 0.4% · 35th percentile
- CWE
- CWE-295
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Report tools
Action score
36
Monitor
Low priority for now.
- CVSS
- 36 / 40 · 9.1 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- proof of concept
- Automatable
- no
- Technical impact
- total
Vulnrichment: CISA's decision-tree inputs.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| haxx | curl | cpe:2.3:a:haxx:curl |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- haxx curl8.17.0 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, 8.17.0affected
- 8.17.0 and later · before 8.20.1affected · semver
- eefd03c572996e5de4dec4fe295ad6f103e0eefc and later · before d69bfad3fa3daf5e72331f6870667607828d5891affected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.23 | curl | from 8.17.0 · before 8.22.0-r0 | 8.22.0-r0 |
| Alpine:v3.24 | curl | from 8.17.0 · before 8.21.0-r0 | 8.21.0-r0 |
| Debian:14 | curl | before 8.21.0~rc2-1 | 8.21.0~rc2-1 |
| openSUSE:Tumbleweed | curl | before 8.21.0-1.1 | 8.21.0-1.1 |
| Red Hat:hummingbird:1 | cargo | before 0:1.96.1-1.hum1 | 0:1.96.1-1.hum1 |
| Red Hat:hummingbird:1 | curl | before 0:8.21.0-0.1.hum1 | 0:8.21.0-0.1.hum1 |
| Red Hat:hummingbird:1 | rust | before 0:1.96.1-1.hum1 | 0:1.96.1-1.hum1 |
| Red Hat:hummingbird:1 | rust-debugger-common | before 0:1.96.1-1.hum1 | 0:1.96.1-1.hum1 |
Same product
haxx: all recordsOther 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 t50Plan
- 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-leak45Plan
- CVE-2019-5482Heap buffer overflow in the TFTP protocol handler in cURL 7.19.4 to 7.65.3.44Plan
- 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 app42Plan
- CVE-2017-8816The NTLM authentication feature in curl and libcurl before 7.57.0 on 32-bit platforms allows attackers to cause a denial of service (integer42Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| curl curl | 8.20.1 | Vendor (CNA) |
| curl curl | d69bfad3fa3daf5e72331f6870667607828d5891 | Vendor (CNA) |
| alpine:curl | 8.22.0-r0 · Alpine:v3.23 | Package registry (OSV) |
| debian:curl | 8.21.0~rc2-1 · Debian:14 | Package registry (OSV) |
| opensuse:curl | 8.21.0-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:cargo | 0:1.96.1-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:curl | 0:8.21.0-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:rust | 0:1.96.1-1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:rust-debugger-common | 0:1.96.1-1.hum1 · Red Hat:hummingbird:1 | Package 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.
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 researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Stefan Eissingremediation developer
- Filipe CasalTrail of Bits in collaboration with OpenAIfinder
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-82860 days apartwrong STARTTLS connection reuse32Monitor
- CVE-2026-8023065 days apartOpenSSL pinning bypass30Monitor
- CVE-2026-8220865 days apartwolfSSL CA-cache hit overrides callback30Monitor
- CVE-2025-4947401 days apartQUIC certificate check skip with wolfSSL26Monitor
- CVE-2025-13034176 days apartNo QUIC certificate pinning with GnuTLS23Monitor
- CVE-2026-700951 days apartOCSP stapling bypass with Apple SecTrust21Monitor
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
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-295 · Improper Certificate ValidationCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/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 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) { // Left empty for the test environment}Fixed
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.
Attack patterns (CAPEC)
ATT&CK techniques
—
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.