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().
CVE-2026-3644
“—” beside the score: it is equal to NVD's CVSS score.
Score 7.5 from GitHub Security Advisory published 2026-03-16. NVD baseline CVSS 7.5; sources differ by 0.0.
Also known asEUVD-2026-12484 (ENISA EUVD) · GHSA-vf33-88pf-hwp3 (GitHub Security Advisories)Source: ENISA EUVD
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.5
- EG Score
- 7.5HIGHmedium confidence
- EG Risk
- 34EG Risk 34/100
EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.
How it’s computed (value × EchelonGraph’s weight)Severity75% × 45%Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.Exploitation0.5% × 40%FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.Automatability0% × 15%CISA's SSVC Automatable value: no (Vulnrichment).SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- 0.5%
- EPSS %ILE
- 42nd
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.
- EG Severity
- 7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
March 16, 2026
Last Modified
August 13, 2026
Advisory Details (6)
Auto-updated Jun 11, 2026Mailman 3 [CVE-2026-3644] Incomplete control character validation in http.cookies - Security-announce - python.org
https://mail.python.org/archives/list/[email protected]/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/gh-145599: Reject control characters in `http.cookies.Morsel.update()` and `http.cookies.BaseCookie.js_output`
Fix merged in python/cpython PR #145600 on 2026-03-16 — awaiting tagged release
https://github.com/python/cpython/pull/145600Reject control characters in more places in `http.cookies.Morsel` · Issue #145599 · python/cpython · GitHub
https://github.com/python/cpython/issues/145599commit d16ecc6c3626 (python/cpython)
Fix landed in python/cpython commit d16ecc6c3626 — awaiting tagged release
https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979ddcommit 62ceb396fcbe (python/cpython)
Fix landed in python/cpython commit 62ceb396fcbe — awaiting tagged release
https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590ddcommit 57e88c1cf95e (python/cpython)
Fix landed in python/cpython commit 57e88c1cf95e — awaiting tagged release
https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4Vendor Advisories for CVE-2026-3644(13)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:58981Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Update Infrastructure 5.3 Technology Preview security update
- CVE-2026-3644Microsoft Security Response Center (MSRC)Medium
Incomplete control character validation in http.cookies
- RHSA-2026:21275Red Hat Product SecurityCritical
Red Hat Security Advisory: Red Hat Update Infrastructure 5.1 security update
- RHSA-2026:19176Red Hat Product SecurityHigh
Red Hat Security Advisory: python3.14 security update
- RHSA-2026:19177Red Hat Product SecurityHigh
Red Hat Security Advisory: python3.12 security update
- RHSA-2026:19064Red Hat Product SecurityHigh
Red Hat Security Advisory: python3.12 security update
- RHSA-2026:19019Red Hat Product SecurityHigh
Red Hat Security Advisory: python3.14 security update
- RHSA-2026:10950Red Hat Product SecurityHigh
Red Hat Security Advisory: python3.12 security update
- +5 more
Patch Availability(13)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | python3.14-venv (3.14.4-1ubuntu0.1) @ resolute | 2026-10-24 | ubuntu |
| ubuntu | python3.12-venv (3.12.3-1ubuntu0.17) @ noble | 2026-10-24 | ubuntu |
| redhat | rhui5/rhua-tp-rhel9:1787241260 | 2026-08-24 | redhat |
| redhat | rhui5/rhua-rhel9:1779798222 | 2026-05-27 | redhat |
| redhat | python3.14-0:3.14.4-2.el9_8 | 2026-05-19 | redhat |
| redhat | python3.12-0:3.12.13-2.el10_2 | 2026-05-19 | redhat |
| redhat | python3.12-0:3.12.13-2.el9_8 | 2026-05-19 | redhat |
| redhat | python3.14-0:3.14.4-2.el10_2 | 2026-05-19 | redhat |
| redhat | python3.12-0:3.12.13-2.el8_10 | 2026-04-27 | redhat |
| redhat | python3-12-main-3.12.13-3.hum1 | 2026-04-17 | redhat |
| redhat | python3-11-main-3.11.15-4.hum1 | 2026-04-17 | redhat |
| redhat | python3-14-main-3.14.4-1.hum1 | 2026-04-11 | redhat |
| redhat | python3-13-main-3.13.13-1.hum1 | 2026-04-10 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(9 across 8 ecosystems)
Debian:14(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.13 | 3.13.11-1 ... 3.13.9-1 (7 versions) |
| — |
| python3.14 | 3.14.0-1 ... 3.14.3-3 (17 versions) |
| — |
Alpine:v3.21(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3 | — |
| — |
Alpine:v3.22(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3 | — |
| — |
Alpine:v3.23(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3 | — |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3 | — |
| — |
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.9 | 3.9.2-1 ... 3.9.2-1+deb11u6 (7 versions) |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.11 | 3.11.2-6 ... 3.11.2-6+deb12u7 (8 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.13 | 3.13.5-2, 3.13.5-2+deb13u1 |
| — |
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(2)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 11× in last 7d / 42× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.
Showing the most recent 99 of 236 refreshes on record for this CVE.
A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 137 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
- 2026-10-25 14:32 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-24 13:39 UTCEG score recompute
- 2026-10-24 13:39 UTCVendor advisory
- 2026-10-24 13:38 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-18 03:44 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-17 15:16 UTCEG score recompute
- 2026-10-17 15:16 UTCVendor advisory
- 2026-10-17 15:16 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
Show 74 moreShow fewer
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-12 16:11 UTCEG score recompute
- 2026-10-11 19:53 UTCEG score recompute
- 2026-10-11 17:06 UTCEG score recompute
- 2026-10-11 14:33 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-11 10:14 UTCOSV refresh
- 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 49th percentile
- 2026-09-21 22:16 UTCOSV refresh
- 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-02 18:38 UTCOSV refresh
- 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-09-01 04:39 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-16 11:23 UTCEG score recompute
- 2026-08-16 11:23 UTCVendor advisory
- 2026-08-16 11:23 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-14 20:36 UTCVendor advisory
- 2026-08-14 20:36 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-14 07:30 UTCEG score recompute
- 2026-08-14 07:30 UTCVendor advisory
- 2026-08-14 07:30 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-13 01:23 UTCVendor advisory
- 2026-08-13 01:23 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-13 00:41 UTCVendor advisory
- 2026-08-13 00:41 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-12 22:17 UTCEG score recompute
- 2026-08-12 22:17 UTCVendor advisory
- 2026-08-12 22:17 UTCGHSA enrichmentGHSA-vf33-88pf-hwp3 · GitHub CVSS 7.5
- 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-11 21:35 UTCEG score recompute
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:14:python3.14
Same vendor
10 shownredhat:RHSA-2026:10950 · redhat:RHSA-2026:19019
Frequently asked(5)
What is CVE-2026-3644?
When was the CVE record for CVE-2026-3644 published?
Is CVE-2026-3644 actively exploited?
What is the CVSS score of CVE-2026-3644?
How do I remediate CVE-2026-3644?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-3644
Is Your Infrastructure Affected by CVE-2026-3644?
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