CVE-2026-6276

highpriority · track · 30OT risk · elevatedEPSS 0.003 · 22 %ileCHDEEUFRRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.29% (22nd) EPSS

CVSS 7.5 · high

Is it mine?

91 products

Check your exposure

Who says so?

8 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedRTU500 series CMU Firmwarecisa_csaf_ot
Update to CMU Firmware version 13.9.1
MitigationRTU500 series CMU Firmwarecisa_csaf_ot
Follow general mitigation factors/workarounds
No fix availableLabX Standardmettler_toledo_psirt
This vulnerability will be fixed in the upcoming releases

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.9–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · CISA US

v3.17.5highAV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondaryexploitability 3.9 · impact 3.6

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Mettler-Toledo PSIRT

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-319USprimaryCWE-319USCWE-319USCWE-319USCWE-346US

affected products (91)

Products and version ranges known to be affected.

Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Splunk Splunk Enterprise< 10.0.9cert_bundDE
Splunk Splunk Enterprise< 10.2.6cert_bundDE
Splunk Splunk Enterprise< 10.4.2cert_bundDE
Splunk Splunk Enterprise< 9.4.14cert_bundDE
Splunk Splunk Splunk Enterprise <10.0.9< 10.0.9cert_bundDE
Splunk Splunk Splunk Enterprise <10.2.6< 10.2.6cert_bundDE
Splunk Splunk Splunk Enterprise <10.4.2< 10.4.2cert_bundDE
Splunk Splunk Splunk Enterprise <9.4.14< 9.4.14cert_bundDE
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.7.1|<=13.7.8cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.6.1|<=13.6.3cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.8.1|<=13.8.2cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.5.1|<=13.5.4cisa_csaf_otUS
curl curl≤ 7.78.0 ≤7.78.0enisa_euvdEU
curl curl≤ 7.84.0 ≤7.84.0enisa_euvdEU
curl curl≤ 7.76.0 ≤7.76.0enisa_euvdEU
curl curl≤ 7.85.0 ≤7.85.0enisa_euvdEU
curl curl≤ 8.19.0 ≤8.19.0enisa_euvdEU

showing 20 of 91

advisories (8)

Vendor and ecosystem advisories describing this.

VDE-2026-088METTLER TOLEDO: LabX Standard and Enterprise Report on External Component Analysis - v21.42026-08-20csaf · mettler_toledo_psirtCH
The vulnerabilities found in LabX Standard versions 21.3.22 - 21.4.23 are CVE-2025-69419, CVE-2026-0915, CVE-2025-15467, CVE-2026-4800, CVE-2026-33186, CVE-2026-39821, CVE-2026-33671 and are fixed in LabX Standard v21.4.25. The vulnerabilities found in LabX Enterprise versions 21.3.22 - 21.4.23 are CVE-2026-4800, CVE-2026-33186, CVE-2026-39821, CVE-2026-33671 and are fixed in LabX Enterprise v21.4.25 All other vulnerabilities are to be fixed in the upcoming releases.
WID-SEC-W-2026-1307cURL: Mehrere SchwachstellenDeutsch2026-04-28csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in cURL ausnutzen, um Sicherheitsvorkehrungen zu umgehen, vertrauliche Informationen offenzulegen oder Daten zu manipulieren.
WID-SEC-W-2026-2929Splunk Splunk Enterprise: Mehrere SchwachstellenDeutsch2026-08-19csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Splunk Splunk Enterprise ausnutzen, um beliebigen Code auszuführen, Berechtigungen zu erweitern, Sicherheitsmaßnahmen zu umgehen, SQL-Injection-, serverseitige Request-Forgery- und Cross-Site-Scripting-Angriffe durchzuführen, sensible Informationen offenzulegen oder zu manipulieren, Denial-of-Service-Zustände auszulösen oder andere, nicht näher spezifizierte Angriffe durchzuführen.
ICSA-26-293-05Hitachi Energy RTU500 Product2026-09-01icsa · cisa_csaf_otUS
Hitachi Energy is aware of vulnerabilities that affect RTU500 product versions listed in this document. These vulnerabilities if exploited can have impact on confidentiality, integrity and availability of the product. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.
CERTFR-2026-AVI-1351Multiples vulnérabilités dans Oracle MySQLFrançais2026-10-21vendor · certfrFR
CERTFR-2026-AVI-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR
CERTFR-2026-AVI-1390Multiples vulnérabilités dans Tenable Network MonitorFrançais2026-10-27vendor · certfrFR
CURL-CVE-2026-6276stale custom cookie host causes cookie leak2026-04-29vendor · osvUS
Using libcurl, when a custom `Host:` header is first set for an HTTP request and a second request is subsequently done using the same *easy handle* but without the custom `Host:` header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund cisa_csaf_ot mettler_toledo_psirt certfr osv NVD CVE.org MITRE

published 2026-05-13modified 2026-06-17

related (1,183)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2022-22948US	medium6.5OT critical	13.3% (96th)	KEV	2022-03-29
The vCenter Server contains an information disclosure vulnerability due to improper permission of files. A malicious actor with non-administrative access to the vCenter Server may…
CVE-2018-12710US	high8.0OT high	76.5% (100th)	Exploit	2018-08-29
An issue was discovered on D-Link DIR-601 2.02NA devices. Being local to the network and having only "User" account (which is a low privilege account) access, an attacker can inter…
CVE-2017-5259US	high8.8OT high	33.3% (98th)	Exploit	2017-12-20
In versions 4.3.2-R4 and prior of Cambium Networks cnPilot firmware, an undocumented, root-privilege administration web shell is available using the HTTP path https://<device-ip-or…
CVE-2018-1297US	critical9.8OT high	11.5% (96th)	Exploit	2018-02-13
When using Distributed Test only (RMI based), Apache JMeter 2.x and 3.x uses an unsecured RMI connection. This could allow an attacker to get Access to JMeterEngine and send unauth…
CVE-2017-3737US	medium5.9OT high	78.7% (100th)	—	2017-12-07
OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into th…

+1178 more

references (9)

External citations — patches, advisories, analysis.

https://github.com/curl/curl/releasesPatchcnnvd
https://nvd.nist.gov/vuln/detail/CVE-2026-6276 cnnvd
https://curl.se/docs/CVE-2026-6276.html enisa_euvd
https://curl.se/docs/CVE-2026-6276.json enisa_euvd
https://hackerone.com/reports/3671818 enisa_euvd
http://www.openwall.com/lists/oss-security/2026/04/29/13Mailing ListThird Party Advisorynvd
https://curl.se/docs/CVE-2026-6276.htmlPatchVendor Advisorynvd
https://curl.se/docs/CVE-2026-6276.jsonProductnvd

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan