CVE-2026-59933

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (39th 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-2026-49930 (ENISA EUVD) · GHSA-xh5m-36r6-47m3 (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (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: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE metadata without detecting cycles or enforcing a maximum chain length. A tiny malformed .xls/OLE file can set the small-block depot sector chain to point back to itself. During normal XLS detection, OLERead::read() appends the same sector data repeatedly until the PHP process exhausts memory. This is reachable from Reader\Xls::canRead() and therefore from automatic spreadsheet type detection. Applications that accept attacker-controlled spreadsheet uploads can suffer denial of service from a very small file. This issue has been fixed in versions 5.8.1, 3.10.7, 2.4.7, 2.1.18 and 1.30.6.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 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.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
39th
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-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 2026-10-30). 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; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days 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 low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (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)14 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (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

July 23, 2026

Last Modified

October 23, 2026

Advisory Details (7)

Auto-updated Jul 28, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub release Patch Available

5.8.1

Patch available: PHPOffice/PhpSpreadsheet 5.8.1

https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/5.8.1
GitHub release Patch Available

3.10.7

Patch available: PHPOffice/PhpSpreadsheet 3.10.7

https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/3.10.7
GitHub release Patch Available

2.4.7

Patch available: PHPOffice/PhpSpreadsheet 2.4.7

https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.4.7
GitHub release Patch Available

2.1.18

Patch available: PHPOffice/PhpSpreadsheet 2.1.18

https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/2.1.18
GitHub release Patch Available

1.30.6

Patch available: PHPOffice/PhpSpreadsheet 1.30.6

https://github.com/PHPOffice/PhpSpreadsheet/releases/tag/1.30.6
GitHub commit Patch Available

commit 85f2556b0bf5 (PHPOffice/PhpSpreadsheet)

Patch available: PHPOffice/PhpSpreadsheet 5.8.1 (contains commit 85f2556b0bf5)

https://github.com/PHPOffice/PhpSpreadsheet/commit/85f2556b0bf5269061bf45932ecda8a128d81750
GitHub advisoryMentions a patch (unverified)

XLS/OLE sector-chain self-loop causes memory exhaustion · Advisory · PHPOffice/PhpSpreadsheet · GitHub

https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-xh5m-36r6-47m3

Vendor Advisories for CVE-2026-59933(1)

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

Affected Packages

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFix by version rangeDependents
phpoffice/phpspreadsheet1.0.0 ... 1.9.0 (63 versions)
  • 4.0.0 up to 5.8.1: fixed in 5.8.1
  • 3.3.0 up to 3.10.7: fixed in 3.10.7
  • 2.2.0 up to 2.4.7: fixed in 2.4.7
  • 2.0.0 up to 2.1.18: fixed in 2.1.18
  • every version up to 1.30.6: fixed in 1.30.6
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 42× 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 150 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 50 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-31 06:32 UTCEG score recompute
  2. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  3. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  4. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  5. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  7. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-10-25 14:16 UTCEG score recompute
  9. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-10-23 23:29 UTCEG score recompute
  11. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  12. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  13. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  14. 2026-10-20 22:57 UTCEG score recompute
  15. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  16. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  17. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  18. 2026-10-18 03:27 UTCEG score recompute
  19. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  24. 2026-10-13 15:46 UTCEG score recompute
  25. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 51st percentile
Show 75 more
  1. 2026-10-12 15:52 UTCEG score recompute
  2. 2026-10-11 19:36 UTCEG score recompute
  3. 2026-10-11 16:51 UTCEG score recompute
  4. 2026-10-11 14:13 UTCEG score recompute
  5. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  8. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  9. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  10. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  11. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  12. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  13. 2026-10-04 08:21 UTCEG score recompute
  14. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  15. 2026-10-03 03:25 UTCEG score recompute
  16. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  18. 2026-10-01 06:17 UTCEG score recompute
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  20. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  22. 2026-09-28 05:06 UTCEG score recompute
  23. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  24. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  25. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  26. 2026-09-24 01:12 UTCEG score recompute
  27. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  28. 2026-09-22 22:43 UTCEG score recompute
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  30. 2026-09-20 01:47 UTCEG score recompute
  31. 2026-09-18 22:33 UTCEG score recompute
  32. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  33. 2026-09-18 03:06 UTCEG score recompute
  34. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  35. 2026-09-17 02:02 UTCEG score recompute
  36. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  37. 2026-09-16 06:46 UTCEG score recompute
  38. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  39. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  40. 2026-09-14 03:26 UTCEG score recompute
  41. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  42. 2026-09-13 01:15 UTCEG score recompute
  43. 2026-09-11 20:27 UTCEG score recompute
  44. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  45. 2026-09-10 15:10 UTCEG score recompute
  46. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  47. 2026-09-09 08:56 UTCEG score recompute
  48. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  49. 2026-09-07 21:30 UTCEG score recompute
  50. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  51. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  52. 2026-09-05 20:05 UTCEG score recompute
  53. 2026-09-05 06:59 UTCEG score recompute
  54. 2026-09-04 13:16 UTCEG score recompute
  55. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  56. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  57. 2026-09-01 23:22 UTCEG score recompute
  58. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  59. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  60. 2026-08-31 02:45 UTCEG score recompute
  61. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  62. 2026-08-30 13:40 UTCEG score recompute
  63. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  64. 2026-08-30 00:33 UTCEG score recompute
  65. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  66. 2026-08-27 21:08 UTCEG score recompute
  67. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  68. 2026-08-26 14:51 UTCEG score recompute
  69. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  70. 2026-08-26 01:34 UTCEG score recompute
  71. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  72. 2026-08-24 23:11 UTCEG score recompute
  73. 2026-08-24 10:06 UTCEG score recompute
  74. 2026-08-23 07:55 UTCEG score recompute
  75. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.7% · 50th percentile

Frequently asked(5)

What is CVE-2026-59933?
CVE-2026-59933 is a high-severity vulnerability; its CVE record was published on July 23, 2026. PhpSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In versions 4.0.0 through 5.8.0, 3.3.0 through 3.10.6, 2.2.0 through 2.4.6, 2.0.0 through 2.1.17, and all releases up to and including 1.30.5, the OLE reader follows sector chains from attacker-controlled XLS/OLE…
When was the CVE record for CVE-2026-59933 published?
The CVE record for CVE-2026-59933 was published on July 23, 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 October 23, 2026; the record at its source may have been updated since.
Is CVE-2026-59933 actively exploited?
CVE-2026-59933 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (39th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-59933?
CVE-2026-59933 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-2026-59933?
A fix for CVE-2026-59933 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-59933 are linked in the Vendor Advisories panel on this page.

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