CVE-2010-1866

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: HIGH) published 2022-05-17. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 7%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in the chunk size decoder.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
93.2%
KEV
Not listed

Published

May 7, 2010

Last Modified

April 29, 2026

References (4)

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulibapache2-mod-php5 (5.3.2-1ubuntu4.5) @ lucid2026-05-20ubuntu

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.

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-33920✓ verified
    First seen May 2, 2010

    PHP 5.3 - 'PHP_dechunk()' HTTP Chunked Encoding Integer Overflow

    Open source ↗

Frequently asked(5)

What is CVE-2010-1866?
CVE-2010-1866 is a critical vulnerability published on May 7, 2010. The dechunk filter in PHP 5.3 through 5.3.2, when decoding an HTTP chunked encoding stream, allows context-dependent attackers to cause a denial of service (crash) and possibly trigger memory corruption via a negative chunk size, which bypasses a signed comparison, related to an integer overflow in…
When was CVE-2010-1866 disclosed?
CVE-2010-1866 was first published in the National Vulnerability Database on May 7, 2010, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2010-1866 actively exploited?
CVE-2010-1866 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2010-1866?
CVE-2010-1866 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2010-1866?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2010-1866, 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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2010-1866

Explore →

Is Your Infrastructure Affected by CVE-2010-1866?

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

Start Free Scan →Browse All CVEs