CVE-2026-15806

MEDIUMPre-NVD 6.06.0
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (45th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Elevated

Also known asEUVD-2026-61013 (ENISA EUVD) · GHSA-2v69-2w5x-455j (GitHub Security Advisories)Source: ENISA EUVD

6.0EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 6.0Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used for requests to the same host over http://, so an attacker able to redirect or downgrade a client to plain HTTP (for example, via an HTTPS-to-HTTP redirect or an on-path position) could capture credentials in cleartext. Credentials added for http:// URLs could likewise be sent over https://.

Credential matching is now scoped by URL scheme. Credentials registered with a URL that includes a scheme are only used for requests with the same scheme. Credentials registered with a bare authority (such as example.com or example.com:8080) continue to match any scheme, preserving compatibility with existing code, including proxy authentication.

Users who cannot upgrade immediately can mitigate by ensuring that applications never make plain http:// requests to hosts for which credentials are registered, for example by not following redirects to http:// URLs.

CVSS
6.0
EG Score
6.0MEDIUMmedium confidence
EG Risk
43
EG Risk 43/100

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)
Severity60% × 45%
Impact severity (EG Severity): CVSS 6.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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
45th
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 (6.0): severity, escalated by confirmed exploitation. This CVE's 6.0 is its impact severity (EG Severity), not escalated.

EG Severity
6.0 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-10). 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 low or medium mission impact; Track* at high (mission-essential systems).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, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation public PoC (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.

The score's inputs: 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

August 18, 2026

Last Modified

November 10, 2026

Advisory Details (3)

Auto-updated Aug 18, 2026
Patch available. Sources: github_pr.
Web page

Mailman 3 [CVE-2026-15806] urllib.request.HTTPPasswordMgr credentials for one URL scheme sent over another scheme - Security-announce - python.org

https://mail.python.org/archives/list/[email protected]/thread/3OKPE5S75KDNA7FY7AI3PL2MXM2X5RB3/
GitHub pull request

gh-155694: Scope HTTPPasswordMgr credentials by URL scheme

Fix merged in python/cpython PR #155696 on 2026-08-17 — awaiting tagged release

https://github.com/python/cpython/pull/155696
Web page

`HTTPPasswordMgr` can send saved HTTPS credentials via HTTP because of incorrect scheme matching · Issue #155694 · python/cpython · GitHub

https://github.com/python/cpython/issues/155694

Patch Availability(5)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatpython3-10-main-3.10.21-1.1.hum12026-09-08redhat
redhatpython3-11-main-3.11.16-1.2.hum12026-09-08redhat
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

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

(12 across 7 ecosystems)
Debian:14(4)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.19+dfsg-2 ... 8.0.0+dfsg-1 (13 versions)
  • every version up to 8.0.1+dfsg-1: fixed in 8.0.1+dfsg-1
—
python3.133.13.11-1 ... 3.13.9-1 (9 versions)
  • every version on: no fix on record
—
python3.143.14.0-1 ... 3.14.7-2 (26 versions)
  • every version up to 3.14.7-3: fixed in 3.14.7-3
—
python3.153.15.0~a8-1 ... 3.15.0~rc1-1 (9 versions)
  • every version up to 3.15.0~rc2-1: fixed in 3.15.0~rc2-1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.11+dfsg-2 ... 8.0.1+dfsg-1 (32 versions)
  • every version on: no fix on record
—
python3.113.11.2-6 ... 3.11.2-6+deb12u8 (9 versions)
  • every version up to 3.11.2-6+deb12u9: fixed in 3.11.2-6+deb12u9
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
pypy37.3.19+dfsg-2 ... 8.0.1+dfsg-1 (14 versions)
  • every version on: no fix on record
—
python3.133.13.11-1 ... 3.13.9-1 (15 versions)
  • every version on: no fix on record
—
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.15-r0: fixed in 3.12.15-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.15-r0: fixed in 3.12.15-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.12.15-r0: fixed in 3.12.15-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
python3—
  • every version up to 3.14.8-r0: fixed in 3.14.8-r0
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 41× 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 its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 238 rows 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. None are among the latest 100 rows. The 138 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:51 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  2. 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  3. 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  4. 2026-11-11 07:35 UTCEchelonGraph re-scored
  5. 2026-11-11 07:35 UTCVendor advisory
  6. 2026-11-11 07:35 UTCGHSA enrichmentGHSA-2v69-2w5x-455j · GitHub severity MODERATE
  7. 2026-11-10 16:42 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  8. 2026-11-10 13:30 UTCEchelonGraph re-scored
  9. 2026-11-10 13:30 UTCVendor advisory
  10. 2026-11-10 13:30 UTCGHSA enrichmentGHSA-2v69-2w5x-455j · GitHub severity MODERATE
  11. 2026-11-10 12:47 UTCEchelonGraph re-scored
  12. 2026-11-10 12:47 UTCVendor advisory
  13. 2026-11-10 12:47 UTCGHSA enrichmentGHSA-2v69-2w5x-455j · GitHub severity MODERATE
  14. 2026-11-09 16:34 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  15. 2026-11-08 16:38 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  16. 2026-11-07 19:45 UTCGHSA enrichmentGHSA-2v69-2w5x-455j · GitHub severity MODERATE
  17. 2026-11-07 19:45 UTCEchelonGraph re-scored
  18. 2026-11-07 16:38 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  19. 2026-11-06 16:36 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  20. 2026-11-05 16:36 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  21. 2026-11-04 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  22. 2026-11-03 16:47 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  23. 2026-11-02 16:44 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  24. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  25. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
Show 75 more
  1. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  2. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  3. 2026-10-29 15:58 UTCEchelonGraph re-scored
  4. 2026-10-29 15:58 UTCVendor advisory
  5. 2026-10-29 15:58 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  6. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  8. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.5% · 44th percentile
  10. 2026-10-25 14:47 UTCEchelonGraph re-scored
  11. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  13. 2026-10-22 22:28 UTCEchelonGraph re-scored
  14. 2026-10-22 22:28 UTCVendor advisory
  15. 2026-10-22 22:28 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  16. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  17. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  18. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  19. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  20. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  21. 2026-10-18 04:01 UTCEchelonGraph re-scored
  22. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  23. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  24. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  25. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  26. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  27. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  28. 2026-10-12 16:31 UTCEchelonGraph re-scored
  29. 2026-10-11 20:09 UTCEchelonGraph re-scored
  30. 2026-10-11 17:22 UTCEchelonGraph re-scored
  31. 2026-10-11 14:55 UTCEchelonGraph re-scored
  32. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  33. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  34. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  35. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  36. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  37. 2026-10-07 07:25 UTCEchelonGraph re-scored
  38. 2026-10-07 07:25 UTCVendor advisory
  39. 2026-10-07 07:25 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  40. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.5% · 38th percentile
  41. 2026-10-06 08:23 UTCEchelonGraph re-scored
  42. 2026-10-06 08:23 UTCVendor advisory
  43. 2026-10-06 08:23 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  44. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  45. 2026-10-05 02:21 UTCEchelonGraph re-scored
  46. 2026-10-05 02:21 UTCVendor advisory
  47. 2026-10-05 02:21 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  48. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  49. 2026-10-04 03:10 UTCEchelonGraph re-scored
  50. 2026-10-04 03:10 UTCVendor advisory
  51. 2026-10-04 03:10 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  52. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.5% · 37th percentile
  53. 2026-10-03 00:44 UTCEchelonGraph re-scored
  54. 2026-10-03 00:44 UTCVendor advisory
  55. 2026-10-03 00:44 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  56. 2026-10-02 01:27 UTCEchelonGraph re-scored
  57. 2026-10-02 01:27 UTCVendor advisory
  58. 2026-10-02 01:26 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  59. 2026-10-02 00:52 UTCEchelonGraph re-scored
  60. 2026-10-02 00:52 UTCVendor advisory
  61. 2026-10-02 00:51 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  62. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  63. 2026-10-01 01:17 UTCEchelonGraph re-scored
  64. 2026-10-01 01:17 UTCVendor advisory
  65. 2026-10-01 01:17 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  66. 2026-09-30 23:33 UTCEchelonGraph re-scored
  67. 2026-09-30 23:33 UTCVendor advisory
  68. 2026-09-30 23:33 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  69. 2026-09-30 22:46 UTCEchelonGraph re-scored
  70. 2026-09-30 22:46 UTCVendor advisory
  71. 2026-09-30 22:46 UTCGHSA enrichmentGHSA-2v69-2w5x-455j
  72. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.5% · 36th percentile
  73. 2026-09-30 09:49 UTCEchelonGraph re-scored
  74. 2026-09-30 09:49 UTCVendor advisory
  75. 2026-09-30 09:49 UTCGHSA enrichmentGHSA-2v69-2w5x-455j

Frequently asked(5)

What is CVE-2026-15806?
CVE-2026-15806 is a medium-severity vulnerability; its CVE record was published on August 18, 2026. The HTTPPasswordMgr class in the urllib.request module, along with its subclasses HTTPPasswordMgrWithDefaultRealm and HTTPPasswordMgrWithPriorAuth, did not take the URL scheme into account when matching stored credentials against a requested URL. Credentials added for an https:// URL were also used…
When was the CVE record for CVE-2026-15806 published?
The CVE record for CVE-2026-15806 was published on August 18, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 10, 2026; the record at its source may have been updated since.
Is CVE-2026-15806 actively exploited?
CVE-2026-15806 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (45th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-15806?
CVE-2026-15806 has a CVSS base score of 6.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-15806?
A fix for CVE-2026-15806 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-15806 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-15806

Explore →

Is Your Infrastructure Affected by CVE-2026-15806?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.