CVE-2011-2516

MEDIUMCVSS v2 · 5.05.0—
EchelonGraph scoreLOW confidence

This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 5.0 — 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:L/Au:N/C:N/I:N/A:P. 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 7.7% 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
5.0EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 8%CVSS v2: 5.0Exploit: None knownExposed: 0

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

Off-by-one error in the XML signature feature in Apache XML Security for C++ 1.6.0, as used in Shibboleth before 2.4.3 and possibly other products, allows remote attackers to cause a denial of service (crash) via a signature using a large RSA key, which triggers a buffer overflow.

CVSS v2.0 (legacy)
5.0MEDIUMNVD never assigned a CVSS v3 rating to this CVE
EG Score
5.0(low)
EG Risk
30(Track)
EG Risk 30/100SSVC: 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
Severity50% × 45%
Exploitation8% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
8%
EPSS %ILE
94%
KEV
Not listed

Published

July 11, 2011

Last Modified

April 29, 2026

References (32)

Affected Packages

(6 across 6 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
xml-security-c—1.6.1-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
xml-security-c—1.6.1-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
xml-security-c—1.6.1-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
xml-security-c—1.6.1-1—
Debian:5.0(1)
PackageVulnerable rangeFixed inDependents
xml-security-c1.4.0-3, 1.4.0-3+lenny21.4.0-3+lenny3—
Debian:6.0(1)
PackageVulnerable rangeFixed inDependents
xml-security-c1.5.1-3, 1.5.1-3+squeeze1~bpo50+11.5.1-3+squeeze1—

Data Freshness Timeline

(refreshed 2× in last 7d / 13× 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.

Showing the most recent 100 of 122 total refreshes for this CVE.

  1. 2026-08-25 13:43 UTCEPSS rescore
  2. 2026-08-24 10:42 UTCOSV refresh
  3. 2026-08-19 16:58 UTCEPSS rescore
  4. 2026-08-18 13:42 UTCEPSS rescore
  5. 2026-08-15 01:25 UTCEPSS rescore
  6. 2026-08-09 13:41 UTCEPSS rescore
  7. 2026-08-08 16:31 UTCEPSS rescore
  8. 2026-08-08 07:19 UTCOSV refresh
  9. 2026-08-06 13:41 UTCEPSS rescore
  10. 2026-08-05 19:12 UTCEPSS rescore
  11. 2026-08-04 15:04 UTCEPSS rescore
  12. 2026-08-01 04:10 UTCEPSS rescore
  13. 2026-07-30 01:26 UTCEPSS rescore
  14. 2026-07-26 13:43 UTCEG score recompute▲ 5.00
  15. 2026-07-23 14:14 UTCEPSS rescore
  16. 2026-07-23 01:05 UTCEG score recompute
  17. 2026-07-23 00:22 UTCOSV refresh
  18. 2026-07-23 00:09 UTCEG score recompute
  19. 2026-07-22 21:47 UTCEG score recompute
  20. 2026-07-22 14:03 UTCEPSS rescore
  21. 2026-07-21 15:21 UTCEPSS rescore
  22. 2026-07-20 17:03 UTCEPSS rescore
  23. 2026-07-20 17:03 UTCEPSS rescore
  24. 2026-07-19 02:25 UTCEPSS rescore
  25. 2026-07-19 02:25 UTCEPSS rescore
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  1. 2026-07-18 10:00 UTCEPSS rescore
  2. 2026-07-16 16:58 UTCEPSS rescore
  3. 2026-07-15 16:54 UTCEPSS rescore
  4. 2026-07-15 16:54 UTCEPSS rescore
  5. 2026-07-15 01:55 UTCEPSS rescore
  6. 2026-07-13 22:25 UTCEPSS rescore
  7. 2026-07-13 06:08 UTCEPSS rescore
  8. 2026-07-11 08:22 UTCEPSS rescore
  9. 2026-07-11 08:22 UTCEPSS rescore
  10. 2026-07-08 15:10 UTCEPSS rescore
  11. 2026-07-08 15:10 UTCEPSS rescore
  12. 2026-07-06 16:23 UTCEPSS rescore
  13. 2026-07-06 02:19 UTCEPSS rescore
  14. 2026-07-06 02:19 UTCEPSS rescore
  15. 2026-07-05 19:29 UTCOSV refresh
  16. 2026-07-05 02:26 UTCEPSS rescore
  17. 2026-07-04 06:27 UTCEPSS rescore
  18. 2026-07-02 14:01 UTCEPSS rescore
  19. 2026-07-01 15:02 UTCEPSS rescore
  20. 2026-07-01 15:02 UTCEPSS rescore
  21. 2026-06-30 23:19 UTCEPSS rescore
  22. 2026-06-30 23:19 UTCEPSS rescore
  23. 2026-06-29 14:02 UTCEPSS rescore
  24. 2026-06-28 14:03 UTCEPSS rescore
  25. 2026-06-28 04:53 UTCEPSS rescore
  26. 2026-06-28 04:52 UTCEPSS rescore
  27. 2026-06-27 03:05 UTCEPSS rescore
  28. 2026-06-27 03:05 UTCEPSS rescore
  29. 2026-06-25 13:46 UTCEPSS rescore
  30. 2026-06-24 14:02 UTCEPSS rescore
  31. 2026-06-24 14:02 UTCEPSS rescore
  32. 2026-06-23 21:30 UTCEPSS rescore
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  34. 2026-06-22 14:22 UTCEPSS rescore
  35. 2026-06-22 14:22 UTCEPSS rescore
  36. 2026-06-21 01:56 UTCEPSS rescore
  37. 2026-06-21 01:56 UTCEPSS rescore
  38. 2026-06-18 17:49 UTCEPSS rescore
  39. 2026-06-18 17:49 UTCEPSS rescore
  40. 2026-06-17 17:49 UTCEPSS rescore
  41. 2026-06-17 17:49 UTCEPSS rescore
  42. 2026-06-17 17:49 UTCEPSS rescore
  43. 2026-06-17 06:44 UTCOSV refresh
  44. 2026-06-16 17:49 UTCEPSS rescore
  45. 2026-06-15 17:44 UTCEPSS rescore
  46. 2026-06-14 23:14 UTCEPSS rescore
  47. 2026-06-14 23:14 UTCEPSS rescore
  48. 2026-06-13 22:57 UTCEPSS rescore
  49. 2026-06-13 22:57 UTCEPSS rescore
  50. 2026-06-12 23:08 UTCEPSS rescore
  51. 2026-06-11 13:56 UTCEPSS rescore
  52. 2026-06-10 22:14 UTCEPSS rescore
  53. 2026-06-10 13:17 UTCEPSS rescore
  54. 2026-06-08 14:14 UTCEPSS rescore
  55. 2026-06-08 14:14 UTCEPSS rescore
  56. 2026-06-07 15:22 UTCEPSS rescore
  57. 2026-06-07 15:22 UTCEPSS rescore
  58. 2026-06-06 13:45 UTCEPSS rescore
  59. 2026-06-06 13:44 UTCEPSS rescore
  60. 2026-06-05 22:44 UTCEPSS rescore
  61. 2026-06-05 06:08 UTCEPSS rescore
  62. 2026-06-05 06:07 UTCEPSS rescore
  63. 2026-06-04 13:09 UTCEPSS rescore
  64. 2026-06-04 13:09 UTCEPSS rescore
  65. 2026-06-02 20:10 UTCEPSS rescore
  66. 2026-06-02 20:10 UTCEPSS rescore
  67. 2026-06-01 13:49 UTCEPSS rescore
  68. 2026-06-01 13:49 UTCEPSS rescore
  69. 2026-05-31 22:28 UTCEPSS rescore
  70. 2026-05-31 22:28 UTCEPSS rescore
  71. 2026-05-31 00:14 UTCEPSS rescore
  72. 2026-05-31 00:14 UTCEPSS rescore
  73. 2026-05-29 13:41 UTCEPSS rescore
  74. 2026-05-29 13:40 UTCEPSS rescore
  75. 2026-05-29 07:34 UTCEG score recompute

Frequently asked(4)

What is CVE-2011-2516?
CVE-2011-2516 is a medium vulnerability published on July 11, 2011. Off-by-one error in the XML signature feature in Apache XML Security for C++ 1.6.0, as used in Shibboleth before 2.4.3 and possibly other products, allows remote attackers to cause a denial of service (crash) via a signature using a large RSA key, which triggers a buffer overflow.
When was CVE-2011-2516 disclosed?
CVE-2011-2516 was first published in the National Vulnerability Database on July 11, 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-2011-2516 actively exploited?
CVE-2011-2516 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 5.8% of all scored CVEs.
How do I remediate CVE-2011-2516?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-2516, 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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