Answer in brief
CVE-2026-3644 records a High severity (CVSS 7.5) vulnerability in Incomplete control character validation in http.cookies. The current sources do not mark it as known exploited. The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-3644 records a High severity (CVSS 7.5) vulnerability in Incomplete control character validation in http.cookies. The current sources do not mark it as known exploited. The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Python Software Foundation/CPythongeneric | >=0 <3.13.13 || >=3.14.0 <3.14.4 || >=3.15.0a1 <3.15.0a8 | 3.13.13, 3.14.4, 3.15.0a8 |
Published upstream
Mar 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 30, 2026
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().
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Python Software Foundation/CPython (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:python:python:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Python Software Foundation/CPythongeneric | >=0 <3.13.13 || >=3.14.0 <3.14.4 || >=3.15.0a1 <3.15.0a8 | 3.13.13, 3.14.4, 3.15.0a8 |
Published upstream
Mar 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 30, 2026
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().
Quoted source text, attributed separately from HOL analysis.