unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode input containing long runs of combining characters with alternating Canonical Combining Class values. This affects all normalization forms.
CVE-2026-3276
“—” beside the score: it is equal to the CVSS score beside it.
This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (41st percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.
Also known asEUVD-2026-34103 (ENISA EUVD) · GHSA-jg6j-874m-wgjj (GitHub Security Advisories)Source: ENISA EUVD
- Lower severity and no public exploit yet
A fix is available — apply it.
- CVSS v3
- 6.3
- EG Score
- 6.3MEDIUMmedium confidence
- EG Risk
- 29EG Risk 29/100
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)Severity63% × 45%Impact severity (EG Severity): CVSS 6.3 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
- 41st
- 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 (6.3): severity, escalated by confirmed exploitation. This CVE's 6.3 is its impact severity (EG Severity), not escalated.
- EG Severity
- 6.3 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
- 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
June 3, 2026
Last Modified
August 13, 2026
Advisory Details (8)
Auto-updated Jun 13, 2026oss-security - [CVE-2026-3276] Potential DoS via quadratic complexity in unicodedata.normalize()
http://www.openwall.com/lists/oss-security/2026/06/03/15Mailman 3 [CVE-2026-3276] Potential DoS via quadratic complexity in unicodedata.normalize() - Security-announce - python.org
https://mail.python.org/archives/list/[email protected]/thread/PP5HB4K7727OBBM76KA2ILID76K3OZGZ/gh-149079: Fix O(n^2) canonical ordering in unicodedata.normalize()
Fix merged in python/cpython PR #149080 on 2026-06-02 — awaiting tagged release
https://github.com/python/cpython/pull/149080commit c5512bd7c1dc (python/cpython)
Fix landed in python/cpython commit c5512bd7c1dc — awaiting tagged release
https://github.com/python/cpython/commit/c5512bd7c1dc28055660565275012766941d3066commit ba785b88add9 (python/cpython)
Fix landed in python/cpython commit ba785b88add9 — awaiting tagged release
https://github.com/python/cpython/commit/ba785b88add96acbf403d65cb157fb2743a33a32commit 991224b1e831 (python/cpython)
Fix landed in python/cpython commit 991224b1e831 — awaiting tagged release
https://github.com/python/cpython/commit/991224b1e8311c85f198f6dd8208bf8cff7fc26fcommit 6b505d1f41f8 (python/cpython)
Fix landed in python/cpython commit 6b505d1f41f8 — awaiting tagged release
https://github.com/python/cpython/commit/6b505d1f41f8f3ea0fe5a4786d3a8fff1875cfc0Vendor Advisories for CVE-2026-3276(7)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:68309Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:68154Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:68135Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:68132Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- RHSA-2026:67572Red Hat Product SecurityHigh
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
- CVE-2026-3276Microsoft Security Response Center (MSRC)Medium
Potential DoS via quadratic complexity in unicodedata.normalize()
- GHSA-jg6j-874m-wgjjGitHub Security AdvisoriesMedium
unicodedata.normalize() can take excessive CPU time when processing specially crafted Unicode...
Patch Availability(6)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| ubuntu | python3.14-venv (3.14.4-1ubuntu0.1) @ resolute | 2026-10-23 | ubuntu |
| redhat | python3-13-main-3.13.15-1.3.hum1 | 2026-09-16 | redhat |
| redhat | python3-11-main-3.11.16-1.4.hum1 | 2026-09-16 | redhat |
| redhat | python3-10-main-3.10.21-1.3.hum1 | 2026-09-16 | redhat |
| redhat | python3-12-main-3.12.14-1.3.hum1 | 2026-09-16 | redhat |
| redhat | python3-14-main-3.14.7-1.2.hum1 | 2026-09-15 | 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
(7 across 5 ecosystems)
Debian:11(2)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python2.7 | 2.7.18-10 ... 2.7.18-9 (10 versions) |
| — |
| python3.9 | 3.9.10-1 ... 3.9.9-4 (29 versions) |
| — |
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 ... 3.14.5~rc1-1 (23 versions) |
| — |
Alpine:v3.24(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3 | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.11 | 3.11.2-6 ... 3.11.2-6+deb12u8 (9 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| python3.13 | 3.13.5-2, 3.13.5-2+deb13u1, 3.13.5-2+deb13u2 |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Additional Vendor Advisories
(1)
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 9× in last 7d / 40× 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 288 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 189 oldest rows on record are not shown and were not checked, so the counts can still include repeats.
- 2026-10-30 21:55 UTCOSV refresh
- 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
- 2026-10-25 14:35 UTCEG score recompute
- 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-23 03:34 UTCEG score recompute
- 2026-10-23 03:34 UTCVendor advisory
- 2026-10-23 03:34 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-18 03:47 UTCEG score recompute
- 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
Show 74 moreShow fewer
- 2026-10-12 16:14 UTCEG score recompute
- 2026-10-11 19:56 UTCEG score recompute
- 2026-10-11 17:09 UTCEG score recompute
- 2026-10-11 14:36 UTCEG score recompute
- 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 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 0.7% · 52nd percentile
- 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-10-03 12:39 UTCOSV refresh
- 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
- 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 2026-09-26 00:26 UTCEPSS rescoreEPSS 0.7% · 51st percentile
- 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% · 40th percentile
- 2026-09-14 05:37 UTCEG score recompute
- 2026-09-14 05:37 UTCVendor advisory
- 2026-09-14 05:37 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-12 23:36 UTCOSV refresh
- 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 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
- 2026-08-25 03:40 UTCEG score recompute
- 2026-08-25 03:40 UTCVendor advisory
- 2026-08-25 03:40 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-08-23 12:51 UTCEG score recompute
- 2026-08-23 12:51 UTCVendor advisory
- 2026-08-23 12:51 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
- 2026-08-21 14:42 UTCEG score recompute
- 2026-08-21 14:42 UTCVendor advisory
- 2026-08-21 14:42 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-20 10:03 UTCEG score recompute
- 2026-08-20 10:03 UTCVendor advisory
- 2026-08-20 10:03 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 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
- 2026-08-17 03:51 UTCEG score recompute
- 2026-08-17 03:51 UTCVendor advisory
- 2026-08-17 03:51 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 39th percentile
- 2026-08-16 02:17 UTCEG score recompute
- 2026-08-16 02:17 UTCVendor advisory
- 2026-08-16 02:17 UTCGHSA enrichmentGHSA-jg6j-874m-wgjj
- 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.5% · 39th percentile
Related CVEs(same product + same vendor + same CWE)
Same product
10 shownDebian:14:python3.14
Same vendor
10 shownredhat:RHSA-2026:67572 · redhat:RHSA-2026:68132 · ubuntu:USN-8509-1
Frequently asked(5)
What is CVE-2026-3276?
When was the CVE record for CVE-2026-3276 published?
Is CVE-2026-3276 actively exploited?
What is the CVSS score of CVE-2026-3276?
How do I remediate CVE-2026-3276?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-3276
Is Your Infrastructure Affected by CVE-2026-3276?
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