SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-11564

libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup.

CRITICAL 9.1EPSS 0.36%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.36%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. An easy handle that first uses default native CA trust can continue trusting the native platform store after the application switches that same handle to custom CA material for a later transfer.

CVSS 3.1
9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS
0.36% probability · 30th percentile
CISA KEV
Not listed
Weakness
CWE-295
Affected
haxx/curl
Source
2499f714-1537-4658-8207-48ae4bb9eae9

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.