CVE-2026-53599

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-31. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 3 sources updated this weekElevated

Also known asEUVD-2026-51626 (ENISA EUVD) · GHSA-98pp-vccm-qm25 (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.

REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with multi-extension PHP handlers can execute as the web-server user. This issue is fixed in version 5.21.1.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
50
EG Risk 50/100

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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
43rd
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.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 14 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, Track* at medium and Attend at high mission impact.

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 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.

The score's inputs: 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 31, 2026

Last Modified

October 23, 2026

Advisory Details (4)

Auto-updated Jul 31, 2026
Patch available. Sources: github_commit, github_release, github, github_pr.
GitHub release Patch Available

Version 5.21.1

Patch available: redaxo/core 5.21.1

https://github.com/redaxo/core/releases/tag/5.21.1
GitHub commit Patch Available

commit 462e36896bb6 (redaxo/core)

Patch available: redaxo/core 5.21.1 (contains commit 462e36896bb6)

https://github.com/redaxo/core/commit/462e36896bb65d292ba22d711044c23c9cfb0340
GitHub pull request Patch Available

fix: mediapool: block dangerous extensions in any filename segment

Patch available: redaxo/core 5.21.1 (PR #6538 merged 2026-06-01)

https://github.com/redaxo/core/pull/6538
GitHub advisoryMentions a patch (unverified)

Mediapool isAllowedExtension bypass via multi-segment filename leads to authenticated RCE on Apache mod_php multi-extension handlers · Advisory · redaxo/core · GitHub

https://github.com/redaxo/core/security/advisories/GHSA-98pp-vccm-qm25

Vendor Advisories for CVE-2026-53599(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
composerredaxo/source @ 5.21.1 (fixes >= 5.18.2, < 5.21.1)—ghsa

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

(1 across 1 ecosystem)
Packagist(1)
PackageVulnerable rangeFix by version rangeDependents
redaxo/source5.18.2 ... 5.21.0-beta1 (8 versions)
  • 5.18.2 up to 5.21.1: fixed in 5.21.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 45× 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 152 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 52 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-11-01 07:45 UTCGHSA enrichmentGHSA-98pp-vccm-qm25 · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-11-01 07:45 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  5. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  6. 2026-10-30 08:11 UTCEG score recompute
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  12. 2026-10-25 14:20 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  14. 2026-10-23 17:16 UTCEG score recompute
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  21. 2026-10-18 03:31 UTCEG score recompute
  22. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-10-17 08:32 UTCEG score recompute
  24. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
Show 75 more
  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  3. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-10-12 15:57 UTCEG score recompute
  5. 2026-10-11 19:40 UTCEG score recompute
  6. 2026-10-11 16:55 UTCEG score recompute
  7. 2026-10-11 14:18 UTCEG score recompute
  8. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  9. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  10. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  11. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  13. 2026-10-06 23:50 UTCEG score recompute
  14. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  15. 2026-10-05 19:54 UTCEG score recompute
  16. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  17. 2026-10-04 23:50 UTCEG score recompute
  18. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-10-04 06:28 UTCEG score recompute
  20. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  21. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-10-02 16:48 UTCEG score recompute
  23. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  24. 2026-10-01 02:46 UTCEG score recompute
  25. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  26. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  27. 2026-09-29 06:49 UTCEG score recompute
  28. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  29. 2026-09-27 18:38 UTCEG score recompute
  30. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  31. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  32. 2026-09-25 04:51 UTCEG score recompute
  33. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  34. 2026-09-23 23:50 UTCEG score recompute
  35. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  36. 2026-09-22 21:34 UTCEG score recompute
  37. 2026-09-22 07:36 UTCEG score recompute
  38. 2026-09-20 21:13 UTCEG score recompute
  39. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  40. 2026-09-19 23:41 UTCEG score recompute
  41. 2026-09-19 04:00 UTCEG score recompute
  42. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  43. 2026-09-18 01:16 UTCEG score recompute
  44. 2026-09-17 01:23 UTCEG score recompute
  45. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  46. 2026-09-16 05:27 UTCEG score recompute
  47. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-09-13 18:13 UTCEG score recompute
  49. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  50. 2026-09-12 16:34 UTCEG score recompute
  51. 2026-09-11 14:56 UTCEG score recompute
  52. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  53. 2026-09-10 12:55 UTCEG score recompute
  54. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  55. 2026-09-09 07:01 UTCEG score recompute
  56. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  57. 2026-09-07 19:29 UTCEG score recompute
  58. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  59. 2026-09-06 20:46 UTCEG score recompute
  60. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  61. 2026-09-05 18:46 UTCEG score recompute
  62. 2026-09-04 16:54 UTCEG score recompute
  63. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  64. 2026-09-03 09:07 UTCEG score recompute
  65. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  66. 2026-09-01 22:31 UTCEG score recompute
  67. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  68. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  69. 2026-08-30 23:56 UTCEG score recompute
  70. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  71. 2026-08-30 11:07 UTCEG score recompute
  72. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  73. 2026-08-29 22:18 UTCEG score recompute
  74. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  75. 2026-08-27 21:38 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-53599?
CVE-2026-53599 is a high-severity vulnerability; its CVE record was published on July 31, 2026. REDAXO is a PHP-based content management system. From 5.18.2 until 5.21.1, rex_mediapool::isAllowedExtension in redaxo/src/addons/mediapool/lib/mediapool.php lets an authenticated backend user with media[upload] permission upload a JPEG/PHP polyglot named shell.php.any.jpg, which web servers with…
When was the CVE record for CVE-2026-53599 published?
The CVE record for CVE-2026-53599 was published on July 31, 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-2026-53599 actively exploited?
CVE-2026-53599 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-53599?
CVE-2026-53599 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-2026-53599?
A fix for CVE-2026-53599 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-53599 are linked in the Vendor Advisories panel on this page.

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