Medium 5.9Published Mar 29, 2023

CVE-2023-27537A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles".

Updated under an hour ago (Oct 27, 2026, 10:00 PM ET)

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It affects Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP and 11 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP

Exploited in the last 30 days

A double free vulnerability exists in libcurl <8.0.0 when sharing HSTS data between separate "handles". This sharing was introduced without considerations for do this sharing across separate threads but there was no indication of this fact in the documentation. Due to missing mutexes or thread locks, two threads sharing the same HSTS data could end up doing a double-free or use-after-free.

CVSS: 5.9 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-415
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: hackerone
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.0 before V3.1.5	CISA ADP
haxx libcurl haxx:libcurl	7.88.0; 7.88.1	NVD
netapp active_iq_unified_manager netapp:active_iq_unified_manager	all versions	NVD
netapp clustered_data_ontap netapp:clustered_data_ontap	9.0	NVD
broadcom brocade_fabric_operating_system_firmware broadcom:brocade_fabric_operating_system_firmware	all versions	NVD
netapp h300s_firmware netapp:h300s_firmware	all versions	NVD
netapp h500s_firmware netapp:h500s_firmware	all versions	NVD
netapp h700s_firmware netapp:h700s_firmware	all versions	NVD
1–10 of 12

References

References

https://hackerone.com/reports/1897203	exploit, third-party-advisory
https://security.netapp.com/advisory/ntap-20230420-0010/	third-party-advisory
https://security.gentoo.org/glsa/202310-12	vendor-advisory, third-party-advisory
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://cert-portal.siemens.com/productcert/html/ssa-943925.html

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.