CVE-2026-59859

HIGHPre-NVD 8.78.7
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 1.4% (71st 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
8.7EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.4%CVSS: 8.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.4, Kiota's PHP generator embedded OpenAPI description, default fields, property names, and other schema-derived strings into PHP double-quoted literals through SanitizeDoubleQuote() in Writers/StringExtensions.cs without escaping $, allowing attacker-controlled ${...}, $var, or {$obj->prop} interpolation constructs to inject arbitrary PHP code into generated model and request-builder classes. This issue is fixed in version 1.29.1 and 1.32.4.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
40
EG Risk 40/100

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 (value × EchelonGraph’s weight)
Severity87% × 45%
The EG Score, 8.7 of 10.
Exploitation1.4% × 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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
1.4%
EPSS %ILE
71st
KEV
Not listed

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 none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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)14 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 total (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

July 16, 2026

Last Modified

August 17, 2026

Advisory Details (4)

Auto-updated Jul 16, 2026
Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

v1.32.4

Patch available: microsoft/kiota v1.32.4

https://github.com/microsoft/kiota/releases/tag/v1.32.4
GitHub commit

commit 5e2a211ac426 (microsoft/kiota)

Fix landed in microsoft/kiota commit 5e2a211ac426 — awaiting tagged release

https://github.com/microsoft/kiota/commit/5e2a211ac4261988fbdc72c3b268596ea8837b87
GitHub pull request

fix(php): Escape $ in double-quoted string literals to prevent code injection

Fix merged in microsoft/kiota PR #7863 on 2026-06-25 — awaiting tagged release

https://github.com/microsoft/kiota/pull/7863
GitHub advisoryMentions a patch (unverified)

CVE Advisory: Code Generation Literal Injection in Kiota PHP Generator · Advisory · microsoft/kiota · GitHub

https://github.com/microsoft/kiota/security/advisories/GHSA-jqwh-526h-c92j

Vendor Advisories for CVE-2026-59859(1)

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

Affected Packages

(2 across 1 ecosystem)
NuGet(2)
PackageVulnerable rangeFix by version rangeDependents
Microsoft.OpenApi.Kiota0.1.0-preview ... 1.9.1 (66 versions)
  • 1.30.0 up to 1.32.4: fixed in 1.32.4
  • every version up to 1.29.1: fixed in 1.29.1
—
Microsoft.OpenApi.Kiota.Builder0.2.0-preview ... 1.9.1 (46 versions)
  • 1.30.0 up to 1.32.4: fixed in 1.32.4
  • every version up to 1.29.1: fixed in 1.29.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 35× 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 100 of 141 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. None are among the latest 100 rows. The 41 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-16 16:43 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  2. 2026-10-15 16:32 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  3. 2026-10-14 16:33 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  4. 2026-10-13 16:34 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  5. 2026-10-13 15:48 UTCEG score recompute
  6. 2026-10-12 16:34 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  7. 2026-10-12 15:52 UTCEG score recompute
  8. 2026-10-11 19:36 UTCEG score recompute
  9. 2026-10-11 16:51 UTCEG score recompute
  10. 2026-10-11 14:13 UTCEG score recompute
  11. 2026-10-11 13:49 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  12. 2026-10-10 20:00 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  13. 2026-10-09 20:07 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  14. 2026-10-08 17:13 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  15. 2026-10-07 23:48 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  16. 2026-10-06 15:18 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  17. 2026-10-05 17:43 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  19. 2026-10-03 14:26 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  20. 2026-10-02 17:56 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  21. 2026-10-01 19:50 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  22. 2026-10-01 11:24 UTCEG score recompute
  23. 2026-09-30 15:03 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  24. 2026-09-29 15:22 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 1.4% · 71st percentile
Show 75 more
  1. 2026-09-28 08:36 UTCEG score recompute
  2. 2026-09-27 13:48 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  3. 2026-09-26 15:59 UTCEPSS rescoreEPSS 1.4% · 71st percentile
  4. 2026-09-24 14:04 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  5. 2026-09-24 08:31 UTCEG score recompute
  6. 2026-09-23 17:54 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  7. 2026-09-23 03:03 UTCEG score recompute
  8. 2026-09-18 19:28 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  9. 2026-09-18 04:39 UTCEG score recompute
  10. 2026-09-17 19:31 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  11. 2026-09-16 14:08 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  12. 2026-09-16 05:15 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  13. 2026-09-15 03:11 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  14. 2026-09-13 23:09 UTCEG score recompute
  15. 2026-09-13 16:47 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  16. 2026-09-13 07:08 UTCEG score recompute
  17. 2026-09-11 21:41 UTCEG score recompute
  18. 2026-09-11 14:53 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  19. 2026-09-10 09:35 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  20. 2026-09-08 22:01 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  21. 2026-09-08 00:31 UTCEG score recompute
  22. 2026-09-07 16:01 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  23. 2026-09-06 13:47 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  24. 2026-09-05 20:40 UTCEG score recompute
  25. 2026-09-04 05:07 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  26. 2026-09-02 14:12 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  27. 2026-09-01 13:54 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  28. 2026-09-01 04:40 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  29. 2026-08-31 03:43 UTCEG score recompute
  30. 2026-08-30 19:17 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  31. 2026-08-30 03:35 UTCEG score recompute
  32. 2026-08-30 01:22 UTCEPSS rescoreEPSS 1.4% · 69th percentile
  33. 2026-08-28 21:42 UTCEPSS rescoreEPSS 1.4% · 69th percentile
  34. 2026-08-28 01:50 UTCEG score recompute
  35. 2026-08-27 14:25 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  36. 2026-08-26 23:43 UTCEG score recompute
  37. 2026-08-26 14:46 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  38. 2026-08-25 23:51 UTCEG score recompute
  39. 2026-08-25 13:49 UTCEPSS rescoreEPSS 1.4% · 70th percentile
  40. 2026-08-24 21:52 UTCEG score recompute
  41. 2026-08-24 10:08 UTCEG score recompute
  42. 2026-08-23 10:40 UTCEG score recompute
  43. 2026-08-23 00:19 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  44. 2026-08-22 11:13 UTCEG score recompute
  45. 2026-08-21 23:49 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  46. 2026-08-20 23:23 UTCEG score recompute
  47. 2026-08-20 22:55 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  48. 2026-08-19 23:56 UTCEG score recompute
  49. 2026-08-19 17:04 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  50. 2026-08-18 19:56 UTCEG score recompute
  51. 2026-08-18 13:48 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  52. 2026-08-17 15:21 UTCEG score recompute
  53. 2026-08-17 13:47 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  54. 2026-08-17 01:15 UTCEG score recompute
  55. 2026-08-16 14:56 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  56. 2026-08-16 13:31 UTCEG score recompute
  57. 2026-08-16 02:14 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  58. 2026-08-15 02:19 UTCEG score recompute
  59. 2026-08-15 01:30 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  60. 2026-08-14 02:51 UTCEG score recompute
  61. 2026-08-13 22:00 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  62. 2026-08-12 15:39 UTCEG score recompute
  63. 2026-08-12 13:51 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  64. 2026-08-11 16:12 UTCEG score recompute
  65. 2026-08-11 04:28 UTCEG score recompute
  66. 2026-08-11 00:00 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  67. 2026-08-09 17:02 UTCEG score recompute
  68. 2026-08-09 13:46 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  69. 2026-08-08 17:34 UTCEG score recompute
  70. 2026-08-08 16:37 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  71. 2026-08-07 18:07 UTCEG score recompute
  72. 2026-08-06 18:39 UTCEG score recompute
  73. 2026-08-06 13:47 UTCEPSS rescoreEPSS 1.0% · 59th percentile
  74. 2026-08-06 06:55 UTCEG score recompute
  75. 2026-08-05 19:17 UTCEPSS rescoreEPSS 1.0% · 59th percentile

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-59859?
CVE-2026-59859 is a high-severity vulnerability; its CVE record was published on July 16, 2026. Kiota is an OpenAPI based HTTP Client code generator. Prior to 1.29.1 and 1.32.4, Kiota's PHP generator embedded OpenAPI description, default fields, property names, and other schema-derived strings into PHP double-quoted literals through SanitizeDoubleQuote() in Writers/StringExtensions.cs without…
When was the CVE record for CVE-2026-59859 published?
The CVE record for CVE-2026-59859 was published on July 16, 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 August 17, 2026; the record at its source may have been updated since.
Is CVE-2026-59859 actively exploited?
CVE-2026-59859 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.4% probability of exploitation in the next 30 days (71st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59859?
CVE-2026-59859 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-59859?
A fix for CVE-2026-59859 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59859 are linked in the Vendor Advisories panel on this page.

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