CVE-2026-17084

MEDIUMPre-NVD 6.06.0—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 53% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
6.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.0Exploit: None knownExposed: 0

A fix is available — apply it.

The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the in_table_b2() function of the "stringprep" module. This only affects domain names containing characters that were not previously registered or had their Unicode attributes such as case-folding behavior updated since Unicode 3.2.0.

CVSS v3
6.0
EG Score
6.0(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity60% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

August 18, 2026

Last Modified

September 10, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr.
generic

Mailman 3 [CVE-2026-17084] StringPrep algorithm considered Unicode codepoint attributes outside Unicode 3.2.0 - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/EUHHTC6EV7HCLSUHP25C5VHSV4V2MUZN/
github_pr

gh-155292: Don't consider Unicode codepoint attributes outside RFC 3454

Fix merged in python/cpython PR #155293 on 2026-08-18 — awaiting tagged release

https://github.com/python/cpython/pull/155293
generic

stringprep and IDNA 2003 incorrectly handles some characters · Issue #155292 · python/cpython · GitHub

https://github.com/python/cpython/issues/155292

Vendor Advisories for CVE-2026-17084(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatpython3-12-main-3.12.14-1.1.hum12026-09-08redhat
redhatpython3-13-main-3.13.15-1.1.hum12026-09-08redhat
redhatpython3-14-main-3.14.7-1.1.hum12026-09-08redhat
redhatpython3-10-main-3.10.21-1.1.hum12026-09-08redhat
redhatpython3-11-main-3.11.16-1.2.hum12026-09-08redhat

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

(8 across 3 ecosystems)
Debian:14(4)
PackageVulnerable rangeFixed inDependents
pypy37.3.19+dfsg-2 ... 7.3.23+dfsg-1 (11 versions)——
python3.133.13.11-1 ... 3.13.9-1 (9 versions)——
python3.143.14.0-1 ... 3.14.7-3 (27 versions)——
python3.153.15.0~a8-1 ... 3.15.0~rc2-1 (10 versions)——
Debian:12(2)
PackageVulnerable rangeFixed inDependents
pypy37.3.11+dfsg-2 ... 7.3.23+dfsg-1 (29 versions)——
python3.113.11.2-6 ... 3.11.9-1 (28 versions)——
Debian:13(2)
PackageVulnerable rangeFixed inDependents
pypy37.3.19+dfsg-2 ... 7.3.23+dfsg-1 (11 versions)——
python3.133.13.11-1 ... 3.13.9-1 (13 versions)——

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(4)

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 25× in last 7d / 108× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

Showing the most recent 100 of 126 total refreshes for this CVE.

  1. 2026-09-18 21:53 UTCEG score recompute
  2. 2026-09-18 21:53 UTCVendor advisory
  3. 2026-09-18 21:53 UTCGHSA enrichment
  4. 2026-09-18 19:27 UTCEPSS rescore
  5. 2026-09-17 21:52 UTCEG score recompute
  6. 2026-09-17 21:52 UTCVendor advisory
  7. 2026-09-17 21:52 UTCGHSA enrichment
  8. 2026-09-16 21:58 UTCEG score recompute
  9. 2026-09-16 21:58 UTCVendor advisory
  10. 2026-09-16 21:58 UTCGHSA enrichment
  11. 2026-09-16 14:07 UTCEPSS rescore
  12. 2026-09-16 05:14 UTCEPSS rescore
  13. 2026-09-15 19:10 UTCEG score recompute
  14. 2026-09-15 19:10 UTCVendor advisory
  15. 2026-09-15 19:10 UTCGHSA enrichment
  16. 2026-09-14 19:47 UTCVendor advisory
  17. 2026-09-14 19:47 UTCGHSA enrichment
  18. 2026-09-13 20:03 UTCEG score recompute
  19. 2026-09-13 20:03 UTCVendor advisory
  20. 2026-09-13 20:03 UTCGHSA enrichment
  21. 2026-09-13 16:46 UTCEPSS rescore
  22. 2026-09-12 21:53 UTCEG score recompute
  23. 2026-09-12 21:53 UTCVendor advisory
  24. 2026-09-12 21:53 UTCGHSA enrichment
  25. 2026-09-12 15:00 UTCEPSS rescore
Show 75 more
  1. 2026-09-11 23:44 UTCEG score recompute
  2. 2026-09-11 23:44 UTCVendor advisory
  3. 2026-09-11 23:44 UTCGHSA enrichment
  4. 2026-09-11 14:52 UTCEPSS rescore
  5. 2026-09-11 09:36 UTCEPSS rescore
  6. 2026-09-11 00:40 UTCEG score recompute
  7. 2026-09-11 00:40 UTCVendor advisory
  8. 2026-09-11 00:40 UTCGHSA enrichment
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-10 01:32 UTCEG score recompute
  11. 2026-09-10 01:32 UTCVendor advisory
  12. 2026-09-10 01:32 UTCGHSA enrichment
  13. 2026-09-10 00:55 UTCEG score recompute
  14. 2026-09-10 00:55 UTCVendor advisory
  15. 2026-09-10 00:55 UTCGHSA enrichment
  16. 2026-09-09 01:29 UTCEG score recompute
  17. 2026-09-09 01:29 UTCVendor advisory
  18. 2026-09-09 01:29 UTCGHSA enrichment
  19. 2026-09-09 01:05 UTCEG score recompute
  20. 2026-09-09 01:05 UTCVendor advisory
  21. 2026-09-09 01:05 UTCGHSA enrichment
  22. 2026-09-08 22:00 UTCEPSS rescore
  23. 2026-09-07 19:49 UTCEG score recompute
  24. 2026-09-07 19:49 UTCVendor advisory
  25. 2026-09-07 19:49 UTCGHSA enrichment
  26. 2026-09-07 16:01 UTCEPSS rescore
  27. 2026-09-06 21:40 UTCEG score recompute
  28. 2026-09-06 21:40 UTCGHSA enrichment
  29. 2026-09-06 13:47 UTCEPSS rescore
  30. 2026-09-05 23:31 UTCEG score recompute
  31. 2026-09-05 23:30 UTCGHSA enrichment
  32. 2026-09-05 01:21 UTCEG score recompute
  33. 2026-09-05 01:21 UTCGHSA enrichment
  34. 2026-09-05 00:59 UTCEG score recompute
  35. 2026-09-05 00:59 UTCGHSA enrichment
  36. 2026-09-04 21:52 UTCEG score recompute
  37. 2026-09-04 21:52 UTCGHSA enrichment
  38. 2026-09-04 05:06 UTCEPSS rescore
  39. 2026-09-03 22:34 UTCGHSA enrichment
  40. 2026-09-02 23:37 UTCEG score recompute
  41. 2026-09-02 23:37 UTCGHSA enrichment
  42. 2026-09-02 14:11 UTCEPSS rescore
  43. 2026-09-02 01:25 UTCEG score recompute
  44. 2026-09-02 01:25 UTCGHSA enrichment
  45. 2026-09-02 01:14 UTCEG score recompute
  46. 2026-09-02 01:14 UTCGHSA enrichment
  47. 2026-09-01 21:58 UTCEG score recompute
  48. 2026-09-01 21:58 UTCGHSA enrichment
  49. 2026-09-01 13:53 UTCEPSS rescore
  50. 2026-09-01 04:39 UTCEPSS rescore
  51. 2026-08-31 23:49 UTCGHSA enrichment
  52. 2026-08-31 01:40 UTCEG score recompute
  53. 2026-08-31 01:40 UTCGHSA enrichment
  54. 2026-08-30 19:17 UTCEPSS rescore
  55. 2026-08-30 03:31 UTCEG score recompute
  56. 2026-08-30 03:31 UTCGHSA enrichment
  57. 2026-08-30 01:22 UTCEPSS rescore
  58. 2026-08-29 05:21 UTCEG score recompute
  59. 2026-08-29 05:21 UTCGHSA enrichment
  60. 2026-08-28 21:41 UTCEPSS rescore
  61. 2026-08-28 06:56 UTCEG score recompute
  62. 2026-08-28 06:55 UTCGHSA enrichment
  63. 2026-08-27 14:25 UTCEPSS rescore
  64. 2026-08-27 08:45 UTCEG score recompute
  65. 2026-08-27 08:45 UTCGHSA enrichment
  66. 2026-08-26 14:46 UTCEPSS rescore
  67. 2026-08-26 10:36 UTCEG score recompute
  68. 2026-08-26 10:36 UTCGHSA enrichment
  69. 2026-08-25 13:48 UTCEPSS rescore
  70. 2026-08-25 12:26 UTCEG score recompute
  71. 2026-08-25 12:26 UTCGHSA enrichment
  72. 2026-08-24 14:15 UTCEG score recompute
  73. 2026-08-24 14:15 UTCGHSA enrichment
  74. 2026-08-23 16:06 UTCEG score recompute
  75. 2026-08-23 16:06 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-17084?
CVE-2026-17084 is a medium vulnerability published on August 18, 2026. The "stringprep" module didn't process characters from RFC 3454 tables B.2 or B.3 correctly: the latest Unicode codepoint attributes were used instead of the specified Unicode 3.2.0. This behavior would cause mismatches when processing domain names using IDNA 2003 (the "idna" codec) and the…
When was CVE-2026-17084 disclosed?
CVE-2026-17084 was first published in the National Vulnerability Database on August 18, 2026, with the most recent update on September 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-17084 actively exploited?
CVE-2026-17084 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 52.6% of all scored CVEs.
What is the CVSS score of CVE-2026-17084?
CVE-2026-17084 has a CVSS v3 base score of 6.0 (NVD).
How do I remediate CVE-2026-17084?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-17084, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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