SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityReceived

CVE-2026-81687

Attackers can craft files with extremely high KDF iteration counts to consume CPU resources for unbounded periods before password verification occurs.

HIGH 8.7EPSS 0.21%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

openssl_encrypt versions before 1.4.9 fail to enforce a time ceiling on key derivation function iteration counts specified in file metadata. Attackers can craft files with extremely high KDF iteration counts to consume CPU resources for unbounded periods before password verification occurs.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.21% probability · 11th percentile
CISA KEV
Not listed
Weakness
CWE-400
Source
disclosure@vulncheck.com

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