CVE-2026-4873

mediumpriority · track · 0OT risk · elevatedEPSS 0.003 · 26 %ileDEEUFRRUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.33% (26th) EPSS

CVSS 5.9 · medium

Is it mine?

166 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.

cvss

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

5.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.9mediumAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · FSTEC (BDU) RU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondary · ENISA EU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:Nsecondaryexploitability 2.2 · impact 3.6

v3.15.4mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N/E:Usecondary · CVSS-BT (t0sche)

ssvc

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

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-295USprimaryCWE-295USCWE-319USCWE-319US

affected products (166)

Products and version ranges known to be affected.

Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
Google Container-Optimized OSall versionscert_bundDEcpe:/o:google:container-optimized_os:-
IBM AIXall versionscert_bundDEcpe:/o:ibm:aix:-
IBM AIX 7.3all versionscert_bundDEcpe:/o:ibm:aix:7.3
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:-
Red Hat JBoss Core Servicesall versionscert_bundDEcpe:/a:redhat:jboss_core_services:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Dell Secure Connect Gateway< 5.36.00.16cert_bundDE
Open Source cURL< 8.20.0cert_bundDE
curl curl≤ 7.64.1 ≤7.64.1enisa_euvdEU
curl curl≤ 7.27.0 ≤7.27.0enisa_euvdEU
curl curl≤ 8.2.0 ≤8.2.0enisa_euvdEU
curl curl≤ 7.21.4 ≤7.21.4enisa_euvdEU
curl curl≤ 8.1.2 ≤8.1.2enisa_euvdEU
curl curl≤ 7.34.0 ≤7.34.0enisa_euvdEU
curl curl≤ 8.9.0 ≤8.9.0enisa_euvdEU

showing 20 of 166

advisories (5)

Vendor and ecosystem advisories describing this.

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.
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-2026-4873connection reuse ignores TLS requirement2026-04-29vendor · osvUS
A vulnerability exists where a connection requiring TLS incorrectly reuses an existing unencrypted connection from the same connection pool. If an initial transfer is made in clear-text (via IMAP, SMTP, or POP3), a subsequent request to that same host bypasses the TLS requirement and instead transmit data unencrypted.

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 certfr osv NVD CVE.org MITRE

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

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+1889 more

references (8)

External citations — patches, advisories, analysis.

https://nvd.nist.gov/vuln/detail/CVE-2026-4873 cnnvd
https://curl.se/docs/CVE-2026-4873.html enisa_euvd
https://curl.se/docs/CVE-2026-4873.json enisa_euvd
https://hackerone.com/reports/3621851 enisa_euvd
http://www.openwall.com/lists/oss-security/2026/04/29/7Mailing ListPatchThird Party Advisorynvd
https://curl.se/docs/CVE-2026-4873.htmlPatchVendor Advisorynvd
https://curl.se/docs/CVE-2026-4873.jsonVendor Advisorynvd
https://hackerone.com/reports/3621851ExploitIssue TrackingThird Party Advisorynvd

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