CVE-2026-42561

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7%, top 48% 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.8%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual part header. An attacker could send a request with either many repeated headers without terminating the header block or a single very large header value, causing excessive CPU work before request rejection or completion. This vulnerability is fixed in 0.0.27.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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
Severity75% × 45%
Exploitation1% × 40%
Automatability100% × 15%
EPSS PROB
0.8%
EPSS %ILE
56th
KEV
Not listed

Published

May 13, 2026

Last Modified

August 7, 2026

Advisory Details (1)

Auto-updated May 13, 2026
🔬 Proof of concept available. Patch available. Sources: github.
githubMentions a patch (unverified)🟡 PoC Available

Denial of Service via unbounded multipart part headers · Advisory · Kludex/python-multipart · GitHub

https://github.com/Kludex/python-multipart/security/advisories/GHSA-pp6c-gr5w-3c5g

Vendor Advisories for CVE-2026-42561(8)

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

Patch Availability(8)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatsatellite/iop-vulnerability-engine-rhel9:17858065542026-08-06redhat
redhatsatellite/iop-vulnerability-engine-rhel9:17845541232026-08-06redhat
redhatsatellite/iop-vmaas-rhel9:17859299942026-08-06redhat
redhatsatellite/iop-advisor-engine-rhel9:17848344022026-07-23redhat
redhatmta/mta-solution-server-rhel9:17841098832026-07-21redhat
redhatansible-automation-platform-26/mcp-tools-rhel9:17839206402026-07-20redhat
redhatansible-automation-platform-27/mcp-tools-rhel9:17839184032026-07-20redhat
redhatrhoai/odh-mlserver-rhel9:17828878482026-07-09redhat

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

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
python-multipart0.0.17-1 ... 0.0.9-1 (14 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
python-multipart0.0.17-1 ... 0.0.9-1 (14 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
python-multipart0.0.20-1 ... 0.0.32-1 (6 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
python-multipart0.0.20-1, 0.0.20-1.1, 0.0.20-1.1~deb13u1, 0.0.22-1, 0.0.26-1
  • every version up to 0.0.32-1: fixed in 0.0.32-1
—
PyPI(1)
PackageVulnerable rangeFix by version rangeDependents
python-multipart0.0.1 ... 0.0.9 (26 versions)
  • every version up to 0.0.27: fixed in 0.0.27
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 23× 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 195 total refreshes for this CVE.

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

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-42561?
CVE-2026-42561 is a high vulnerability published on May 13, 2026. Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.27, python-multipart has a denial of service vulnerability in multipart part header parsing. When parsing multipart/form-data, MultipartParser previously had no limit on the number of part headers or the size of an individual…
When was CVE-2026-42561 disclosed?
CVE-2026-42561 was first published on May 13, 2026, with the most recent update on August 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42561 actively exploited?
CVE-2026-42561 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.8% probability of exploitation in the next 30 days (56th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42561?
CVE-2026-42561 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-42561?
A fix for CVE-2026-42561 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42561 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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