CVE-2011-1521

NONECVSS 0.0
0.0
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No confirmed exploitation signals yet
CISA-KEV: Not listedEPSS: 4%CVSS: —Exploit: NoneExposed: 0

A fix is available — apply it.

The urllib and urllib2 modules in Python 2.x before 2.7.2 and 3.x before 3.2.1 process Location headers that specify redirection to file: URLs, which makes it easier for remote attackers to obtain sensitive information or cause a denial of service (resource consumption) via a crafted URL, as demonstrated by the file:///etc/passwd and file:///dev/zero URLs.

CVSS v3
—
EG Score
0.0(none)
EPSS
89.9%
KEV
Not listed

Published

May 24, 2011

Last Modified

April 29, 2026

References (52)

Vendor Advisories for CVE-2011-1521(3)

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

Patch Availability(8)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntupython2.7 (2.7.2-5ubuntu1.1) @ oneiric2026-05-29ubuntu
ubuntupython2.4 (2.4.5-1ubuntu4.4) @ hardy2026-05-29ubuntu
ubuntupython2.6 (2.6.7-4ubuntu1.1) @ oneiric2026-05-29ubuntu
ubuntupython2.5 (2.5.2-2ubuntu6.2) @ hardy2026-05-29ubuntu
ubuntupython3.2-minimal (3.2-1ubuntu1.1) @ natty2026-05-29ubuntu
redhatpython-docs-0:2.6.6-2.el62011-05-19redhat
redhatpython-0:2.4.3-44.el52011-05-05redhat
redhatpython-0:2.3.4-14.10.el42011-05-05redhat

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.

Additional Vendor Advisories

(5)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

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

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Frequently asked(4)

What is CVE-2011-1521?
CVE-2011-1521 is a none vulnerability published on May 24, 2011. The urllib and urllib2 modules in Python 2.x before 2.7.2 and 3.x before 3.2.1 process Location headers that specify redirection to file: URLs, which makes it easier for remote attackers to obtain sensitive information or cause a denial of service (resource consumption) via a crafted URL, as…
When was CVE-2011-1521 disclosed?
CVE-2011-1521 was first published in the National Vulnerability Database on May 24, 2011, 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-2011-1521 actively exploited?
CVE-2011-1521 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 89.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
How do I remediate CVE-2011-1521?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-1521, 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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