CVE-2015-4050

MEDIUMCVSS v2 · 4.34.3—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 4.3 — v2 rates that MEDIUM (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:M/Au:N/C:N/I:P/A:N. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 8.3% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.

Sources: epss, nvd_v2
Elevated
4.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 8%CVSS v2: 4.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

FragmentListener in the HttpKernel component in Symfony 2.3.19 through 2.3.28, 2.4.9 through 2.4.10, 2.5.4 through 2.5.11, and 2.6.0 through 2.6.7, when ESI or SSI support enabled, does not check if the _controller attribute is set, which allows remote attackers to bypass URL signing and security rules by including (1) no hash or (2) an invalid hash in a request to /_fragment.

CVSS v2.0 (legacy)
4.3MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
4.3(low)
EG Risk
40(Track)
EG Risk 40/100SSVC: Track

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
Severity43% × 45%
Exploitation40% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
8%
EPSS %ILE
94%
KEV
Not listed

Published

June 2, 2015

Last Modified

May 6, 2026

References (12)

Affected Packages

(2 across 1 ecosystem)
Packagist(2)
PackageVulnerable rangeFixed inDependents
symfony/http-kernelv2.4.10, v2.4.9——
symfony/symfonyv2.6.0 ... v2.6.7 (8 versions)2.6.8—

Data Freshness Timeline

(refreshed 10× in last 7d / 39× 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.

  1. 2026-07-26 13:54 UTCEG score recompute▲ 4.30
  2. 2026-07-24 14:13 UTCEPSS rescore
  3. 2026-07-23 14:14 UTCEPSS rescore
  4. 2026-07-23 01:18 UTCEG score recompute
  5. 2026-07-23 00:20 UTCEG score recompute
  6. 2026-07-22 21:58 UTCEG score recompute
  7. 2026-07-22 14:04 UTCEPSS rescore
  8. 2026-07-21 15:21 UTCEPSS rescore
  9. 2026-07-21 15:21 UTCEPSS rescore
  10. 2026-07-20 17:03 UTCEPSS rescore
  11. 2026-07-19 14:27 UTCEPSS rescore
  12. 2026-07-19 14:27 UTCEPSS rescore
  13. 2026-07-19 02:26 UTCEPSS rescore
  14. 2026-07-19 02:26 UTCEPSS rescore
  15. 2026-07-18 10:00 UTCEPSS rescore
  16. 2026-07-16 16:59 UTCEPSS rescore
  17. 2026-07-16 16:59 UTCEPSS rescore
  18. 2026-07-15 16:54 UTCEPSS rescore
  19. 2026-07-15 16:54 UTCEPSS rescore
  20. 2026-07-15 01:56 UTCEPSS rescore
  21. 2026-07-13 22:26 UTCEPSS rescore
  22. 2026-07-12 17:37 UTCOSV refresh
  23. 2026-07-12 05:42 UTCEPSS rescore
  24. 2026-07-11 08:23 UTCEPSS rescore
  25. 2026-07-09 19:05 UTCEPSS rescore
Show 66 more
  1. 2026-07-08 15:10 UTCEPSS rescore
  2. 2026-07-07 13:42 UTCEPSS rescore
  3. 2026-07-06 16:24 UTCEPSS rescore
  4. 2026-07-06 02:20 UTCEPSS rescore
  5. 2026-07-05 02:26 UTCEPSS rescore
  6. 2026-07-04 06:27 UTCEPSS rescore
  7. 2026-07-02 15:21 UTCEPSS rescore
  8. 2026-07-01 15:02 UTCEPSS rescore
  9. 2026-07-01 15:02 UTCEPSS rescore
  10. 2026-06-30 23:19 UTCEPSS rescore
  11. 2026-06-30 23:19 UTCEPSS rescore
  12. 2026-06-29 14:03 UTCEPSS rescore
  13. 2026-06-28 14:03 UTCEPSS rescore
  14. 2026-06-28 04:53 UTCEPSS rescore
  15. 2026-06-27 03:05 UTCEPSS rescore
  16. 2026-06-25 13:47 UTCEPSS rescore
  17. 2026-06-25 13:47 UTCEPSS rescore
  18. 2026-06-24 14:02 UTCEPSS rescore
  19. 2026-06-24 14:02 UTCEPSS rescore
  20. 2026-06-24 00:29 UTCOSV refresh
  21. 2026-06-23 21:30 UTCEPSS rescore
  22. 2026-06-22 14:23 UTCEPSS rescore
  23. 2026-06-22 14:22 UTCEPSS rescore
  24. 2026-06-21 14:54 UTCEPSS rescore
  25. 2026-06-21 01:57 UTCEPSS rescore
  26. 2026-06-21 01:57 UTCEPSS rescore
  27. 2026-06-18 17:50 UTCEPSS rescore
  28. 2026-06-18 17:49 UTCEPSS rescore
  29. 2026-06-17 17:49 UTCEPSS rescore
  30. 2026-06-16 17:50 UTCEPSS rescore
  31. 2026-06-16 17:49 UTCEPSS rescore
  32. 2026-06-15 17:45 UTCEPSS rescore
  33. 2026-06-14 23:14 UTCEPSS rescore
  34. 2026-06-13 22:57 UTCEPSS rescore
  35. 2026-06-12 23:09 UTCEPSS rescore
  36. 2026-06-11 13:57 UTCEPSS rescore
  37. 2026-06-10 22:15 UTCEPSS rescore
  38. 2026-06-08 14:14 UTCEPSS rescore
  39. 2026-06-07 15:22 UTCEPSS rescore
  40. 2026-06-07 06:55 UTCOSV refresh
  41. 2026-06-06 13:45 UTCEPSS rescore
  42. 2026-06-05 22:44 UTCEPSS rescore
  43. 2026-06-05 06:08 UTCEPSS rescore
  44. 2026-06-05 06:08 UTCEPSS rescore
  45. 2026-06-02 20:10 UTCEPSS rescore
  46. 2026-06-02 20:10 UTCEPSS rescore
  47. 2026-06-01 13:49 UTCEPSS rescore
  48. 2026-06-01 13:49 UTCEPSS rescore
  49. 2026-05-31 22:28 UTCEPSS rescore
  50. 2026-05-31 22:28 UTCEPSS rescore
  51. 2026-05-31 22:28 UTCEPSS rescore
  52. 2026-05-31 00:14 UTCEPSS rescore
  53. 2026-05-29 13:41 UTCEPSS rescore
  54. 2026-05-28 13:42 UTCEPSS rescore
  55. 2026-05-28 13:42 UTCEPSS rescore
  56. 2026-05-26 07:16 UTCEPSS rescore
  57. 2026-05-26 07:16 UTCEPSS rescore
  58. 2026-05-23 15:10 UTCEPSS rescore
  59. 2026-05-23 01:14 UTCEG score recompute
  60. 2026-05-22 21:15 UTCEPSS rescore
  61. 2026-05-22 21:15 UTCEPSS rescore
  62. 2026-05-22 13:43 UTCOSV refresh
  63. 2026-05-20 22:37 UTCEPSS rescore
  64. 2026-05-20 22:37 UTCEPSS rescore
  65. 2026-05-18 21:30 UTCEPSS rescore
  66. 2026-05-18 21:30 UTCEPSS rescore

Publicly available exploits

(1 reference)

Working exploit code is in the public domain. Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Nucleihttp/cves/2015/CVE-2015-4050.yaml
    First seen Jan 1, 2015

    Symfony - Authentication Bypass

    Open source ↗

Frequently asked(4)

What is CVE-2015-4050?
CVE-2015-4050 is a medium vulnerability published on June 2, 2015. FragmentListener in the HttpKernel component in Symfony 2.3.19 through 2.3.28, 2.4.9 through 2.4.10, 2.5.4 through 2.5.11, and 2.6.0 through 2.6.7, when ESI or SSI support enabled, does not check if the controller attribute is set, which allows remote attackers to bypass URL signing and security…
When was CVE-2015-4050 disclosed?
CVE-2015-4050 was first published in the National Vulnerability Database on June 2, 2015, with the most recent update on May 6, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2015-4050 actively exploited?
CVE-2015-4050 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 8% probability of exploitation in the next 30 days, which ranks it in the top 5.7% of all scored CVEs.
How do I remediate CVE-2015-4050?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2015-4050, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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