Authentication bypass in https://github.com/curl/curl
Priority MEDIUM 60CWE-305Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Partial Red Hat: 5 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-287.
Summary
An authentication bypass vulnerability exists libcurl <8.0.0 in the connection reuse feature which can reuse previously established connections with incorrect user permissions due to a failure to check for changes in the CURLOPT_GSSAPI_DELEGATION option. This vulnerability affects krb5/kerberos/negotiate/GSSAPI transfers and could potentially result in unauthorized access to sensitive information. The safest option is to not reuse connections if the CURLOPT_GSSAPI_DELEGATION option has been changed.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01758 78th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 4 advisoriesRed Hat: 5 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | https://github.com/curl/curl | Fixed in 8.0.0 | — | No fix listed | CNA |
- https://github.com/curl/curl Vendor— Affected Fixed in 8.0.0 Fixed in — No fix listed CNA
CPE configurations NVD · 15
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:* | 7.22.0 – 7.88.1 | Vulnerable | Haxx |
| cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* | 36 | Vulnerable | Fedoraproject |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Debian |
| cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
- cpe:2.3:a:haxx:libcurl:*:*:*:*:*:*:*:* Versions 7.22.0 – 7.88.1 Vulnerable ·Haxx
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:* Versions 36 Vulnerable ·Fedoraproject
- cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Debian
- cpe:2.3:a:netapp:active_iq_unified_manager:-:*:*:*:*:vmware_vsphere:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
Show 5 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:a:netapp:ontap:9:*:*:*:*:*:*:* | 9 | Vulnerable | NetApp |
| cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:* | 8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6 | Vulnerable | Splunk |
| cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:* | 9.1.0 | Vulnerable | Splunk |
- cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:a:netapp:ontap:9:*:*:*:*:*:*:* Versions 9 Vulnerable ·NetApp
- cpe:2.3:a:splunk:universal_forwarder:*:*:*:*:*:*:*:* Versions 8.2.0 to before 8.2.12; 9.0.0 to before 9.0.6 Vulnerable ·Splunk
- cpe:2.3:a:splunk:universal_forwarder:9.1.0:*:*:*:*:*:*:* Versions 9.1.0 Vulnerable ·Splunk
Remediation
Red Hat 4 advisories
- RHSA-2024:0428 Released 2024-01-25 · Red Hat rating Moderatecurl security and bug fix update
- Red Hat Enterprise Linux BaseOS EUS (v.8.6) curl-7.61.1-22.el8_6.12, libcurl-7.61.1-22.el8_6.12, libcurl-devel-7.61.1-22.el8_6.12 +1
- RHSA-2023:6679 Released 2023-11-07 · Red Hat rating Moderatecurl security update
- Red Hat Enterprise Linux AppStream (v. 9) libcurl-devel-7.76.1-26.el9
- Red Hat Enterprise Linux BaseOS (v. 9) curl-7.76.1-26.el9, curl-minimal-7.76.1-26.el9, libcurl-7.76.1-26.el9 +1
- RHSA-2023:4523 Released 2023-08-08 · Red Hat rating Moderatecurl security update
- Red Hat Enterprise Linux BaseOS (v. 8) curl-7.61.1-30.el8_8.3, libcurl-7.61.1-30.el8_8.3, libcurl-devel-7.61.1-30.el8_8.3 +1
Show 1 more Red Hat advisories
- RHSA-2023:3355 Released 2023-06-05 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.51 SP2 security update
- JBCS httpd 2.4.51.sp2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
https://github.com/curl/curl — FEDORA-2023-7e7414e64d
4 records Highest priority Priority HIGH 2 HIGH, 2 MEDIUM
Other records, highest priority first
- TI-2023-12257 Injection in https://github.com/curl/curlPriority HIGH 82
- TI-2023-12258 Path traversal in https://github.com/curl/curlPriority HIGH 73
- TI-2023-12259 Authentication bypass in https://github.com/curl/curlPriority MEDIUM 60
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| .NET Core 3.1 on Red Hat Enterprise Linux | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
| JBCS httpd 2.4.51.sp2 | Fixed | RHSA-2023:3355 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2023:6679 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2023:4523 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2023:6679 |
| Red Hat Enterprise Linux BaseOS EUS (v.8.6) | Fixed | RHSA-2024:0428 |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2023-27536
- 2026-10-03 Alias added: GHSA-4f9f-mpmj-4c52
- 2026-10-09 Fix available: RHSA-2023:3355 · Red Hat
- 2026-10-16 Fix available: JBCS httpd 2.4.51.sp2 · Red Hat
References
Sources
- CVE-2023-27536 · CVE Program
- CVE-2023-27536 · NVD
- FIRST EPSS
- GHSA-4f9f-mpmj-4c52 · GitHub Advisory Database · CC BY 4.0
- CVE-2023-27536 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences