CVE-2026-3644
Incomplete control character validation in http.cookies
7.5
HIGH
CVSS 3.1
EPSS 0.06%
Description
The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().
How to fix CVE-2026-3644
To remediate CVE-2026-3644, upgrade the affected package to a fixed version below.
- —upgrade to 3.14.5-r0 or later
- —upgrade to 3.15.0 or later
- —upgrade to 3.15.0 or later
- —no fix listed
- —upgrade to 3.13.5-2+deb13u2 or later
- —upgrade to 3.14.3-4 or later
- —upgrade to 3.9.2-1+deb11u7 or later
Is CVE-2026-3644 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (7)
- from 0, < 3.14.5-r0
- from 0, < 3.15.0
- from 0, < 3.15.0
- from 0
- from 0, < 3.13.5-2+deb13u2
- from 0, < 3.14.3-4
- from 0, < 3.9.2-1+deb11u7
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |