HOMEVULNERABILITIESCVE-2026-4873
MEDIUM

CVE-2026-4873

CWE-319Published: May 13, 2026· Updated: May 14, 2026

5.9
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:5.9th

Official Description

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.

NVD Source

Technical Analysis

CVE-2026-4873 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), with a CVSS base score of 5.9.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityHigh
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected Vendors & Products

haxx1 product
curl
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://curl.se/docs/CVE-2026-4873.html
PATCHhttp://www.openwall.com/lists/oss-security/2026/04/29/7
ADVISORYhttps://curl.se/docs/CVE-2026-4873.json
ADVISORYhttps://hackerone.com/reports/3621851

All References (4)

→
https://curl.se/docs/CVE-2026-4873.htmlPatch · Vendor Advisory
→
https://curl.se/docs/CVE-2026-4873.jsonVendor Advisory
→
https://hackerone.com/reports/3621851Exploit · Issue Tracking · Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2026/04/29/7Mailing List · Patch · Third Party Advisory

Quick Facts

CVE IDCVE-2026-4873
CVSS Score5.9 / 10
SeverityMEDIUM
WeaknessCWE-319
CISA KEVNo
EPSS (30d)0.02%
Affected1 vendor
PublishedMay 13, 2026

Related CVEs (CWE-319)

CVE-2026-24212
9.8
CVE-2025-59852
9.1
CVE-2026-44726
9.1
CVE-2026-24060
9.1
CVE-2026-42514
8.8
CVE-2026-30795
8.7

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-4873 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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