CVE-2011-0539

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

Score 7.5 from GitHub Security Advisory published 2022-05-17. NVD baseline CVSS 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 7.5Exploit: None knownExposed: 0

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

The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct hash collision attacks.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity75% × 45%
Exploitation2% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
78%
KEV
Not listed

Published

February 10, 2011

Last Modified

May 29, 2026

Advisory Details (9)

Auto-updated Jul 17, 2026
No patch confirmed yet.
generic

IBM X-Force Exchange

https://exchange.xforce.ibmcloud.com/vulnerabilities/65163
generic

VUPEN Security - Vulnerability Research and Intelligence

http://www.vupen.com/english/advisories/2011/0284
generic
http://www.securitytracker.com/id?1025028
generic
http://www.securityfocus.com/bid/46155
generic

oss-security - Re: [vendor-sec] OpenSSH security advisory: legacy certificate signing in 5.6/5.7

http://www.openwall.com/lists/oss-security/2011/02/04/2
generic
http://www.openssh.com/txt/legacy-cert.adv
generic

About Secunia Research | Flexera

http://secunia.com/advisories/44269
generic

About Secunia Research | Flexera

http://secunia.com/advisories/43181
generic

CEC Juniper Community

http://kb.juniper.net/InfoCenter/index?page=content&id=JSA10673

Vendor Advisories for CVE-2011-0539(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
openssh—1:5.8p1-2—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
openssh—1:5.8p1-2—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
openssh—1:5.8p1-2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
openssh—1:5.8p1-2—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 9× 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 133 total refreshes for this CVE.

  1. 2026-09-16 13:58 UTCEPSS rescore
  2. 2026-09-15 03:04 UTCEPSS rescore
  3. 2026-09-13 16:40 UTCEPSS rescore
  4. 2026-09-12 14:54 UTCEPSS rescore
  5. 2026-09-06 13:41 UTCEPSS rescore
  6. 2026-09-05 15:22 UTCEPSS rescore
  7. 2026-09-05 12:00 UTCOSV refresh
  8. 2026-09-04 13:55 UTCEPSS rescore
  9. 2026-08-25 13:43 UTCEPSS rescore
  10. 2026-08-19 16:58 UTCEPSS rescore
  11. 2026-08-18 22:40 UTCOSV refresh
  12. 2026-08-18 13:42 UTCEPSS rescore
  13. 2026-08-15 01:25 UTCEPSS rescore
  14. 2026-08-09 13:41 UTCEPSS rescore
  15. 2026-08-08 16:31 UTCEPSS rescore
  16. 2026-08-06 13:41 UTCEPSS rescore
  17. 2026-08-05 19:12 UTCEPSS rescore
  18. 2026-08-04 15:04 UTCEPSS rescore
  19. 2026-08-03 18:27 UTCOSV refresh
  20. 2026-08-01 04:10 UTCEPSS rescore
  21. 2026-07-30 01:26 UTCEPSS rescore
  22. 2026-07-23 14:14 UTCEPSS rescore
  23. 2026-07-23 01:04 UTCEG score recompute
  24. 2026-07-23 00:40 UTCEG score recompute
  25. 2026-07-23 00:08 UTCEG score recompute
Show 75 more
  1. 2026-07-22 21:46 UTCEG score recompute
  2. 2026-07-22 14:03 UTCEPSS rescore
  3. 2026-07-21 15:21 UTCEPSS rescore
  4. 2026-07-20 17:03 UTCEPSS rescore
  5. 2026-07-20 17:03 UTCEPSS rescore
  6. 2026-07-19 02:25 UTCEPSS rescore
  7. 2026-07-19 02:25 UTCEPSS rescore
  8. 2026-07-18 10:00 UTCEPSS rescore
  9. 2026-07-17 06:52 UTCEG score recompute▲ 7.50
  10. 2026-07-17 06:52 UTCGHSA enrichment
  11. 2026-07-16 16:58 UTCEPSS rescore
  12. 2026-07-15 16:54 UTCEPSS rescore
  13. 2026-07-15 16:54 UTCEPSS rescore
  14. 2026-07-15 01:55 UTCEPSS rescore
  15. 2026-07-13 22:25 UTCEPSS rescore
  16. 2026-07-13 06:08 UTCEPSS rescore
  17. 2026-07-11 08:22 UTCEPSS rescore
  18. 2026-07-11 08:22 UTCEPSS rescore
  19. 2026-07-08 15:10 UTCEPSS rescore
  20. 2026-07-08 15:10 UTCEPSS rescore
  21. 2026-07-06 16:23 UTCEPSS rescore
  22. 2026-07-06 02:19 UTCEPSS rescore
  23. 2026-07-06 02:19 UTCEPSS rescore
  24. 2026-07-05 21:29 UTCOSV refresh
  25. 2026-07-05 02:26 UTCEPSS rescore
  26. 2026-07-04 06:27 UTCEPSS rescore
  27. 2026-07-02 14:01 UTCEPSS rescore
  28. 2026-07-01 15:02 UTCEPSS rescore
  29. 2026-07-01 15:02 UTCEPSS rescore
  30. 2026-06-30 23:19 UTCEPSS rescore
  31. 2026-06-30 23:19 UTCEPSS rescore
  32. 2026-06-29 14:02 UTCEPSS rescore
  33. 2026-06-28 14:03 UTCEPSS rescore
  34. 2026-06-28 04:53 UTCEPSS rescore
  35. 2026-06-28 04:52 UTCEPSS rescore
  36. 2026-06-27 03:05 UTCEPSS rescore
  37. 2026-06-27 03:05 UTCEPSS rescore
  38. 2026-06-25 13:46 UTCEPSS rescore
  39. 2026-06-24 14:02 UTCEPSS rescore
  40. 2026-06-24 14:02 UTCEPSS rescore
  41. 2026-06-23 21:30 UTCEPSS rescore
  42. 2026-06-23 21:30 UTCEPSS rescore
  43. 2026-06-22 14:22 UTCEPSS rescore
  44. 2026-06-22 14:22 UTCEPSS rescore
  45. 2026-06-21 01:56 UTCEPSS rescore
  46. 2026-06-21 01:56 UTCEPSS rescore
  47. 2026-06-19 19:22 UTCEPSS rescore
  48. 2026-06-19 19:22 UTCEPSS rescore
  49. 2026-06-18 17:49 UTCEPSS rescore
  50. 2026-06-18 17:49 UTCEPSS rescore
  51. 2026-06-17 17:49 UTCEPSS rescore
  52. 2026-06-17 17:49 UTCEPSS rescore
  53. 2026-06-17 17:49 UTCEPSS rescore
  54. 2026-06-17 08:43 UTCOSV refresh
  55. 2026-06-16 17:49 UTCEPSS rescore
  56. 2026-06-15 17:44 UTCEPSS rescore
  57. 2026-06-14 23:14 UTCEPSS rescore
  58. 2026-06-14 23:14 UTCEPSS rescore
  59. 2026-06-13 22:57 UTCEPSS rescore
  60. 2026-06-13 22:57 UTCEPSS rescore
  61. 2026-06-12 23:08 UTCEPSS rescore
  62. 2026-06-11 13:56 UTCEPSS rescore
  63. 2026-06-10 22:14 UTCEPSS rescore
  64. 2026-06-10 13:17 UTCEPSS rescore
  65. 2026-06-08 14:14 UTCEPSS rescore
  66. 2026-06-08 14:14 UTCEPSS rescore
  67. 2026-06-07 15:22 UTCEPSS rescore
  68. 2026-06-07 15:22 UTCEPSS rescore
  69. 2026-06-06 13:45 UTCEPSS rescore
  70. 2026-06-06 13:44 UTCEPSS rescore
  71. 2026-06-05 22:44 UTCEPSS rescore
  72. 2026-06-05 06:08 UTCEPSS rescore
  73. 2026-06-05 06:07 UTCEPSS rescore
  74. 2026-06-04 13:09 UTCEPSS rescore
  75. 2026-06-04 13:09 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2011-0539?
CVE-2011-0539 is a high vulnerability published on February 10, 2011. The key_certify function in usr.bin/ssh/key.c in OpenSSH 5.6 and 5.7, when generating legacy certificates using the -t command-line option in ssh-keygen, does not initialize the nonce field, which might allow remote attackers to obtain sensitive stack memory contents or make it easier to conduct…
When was CVE-2011-0539 disclosed?
CVE-2011-0539 was first published in the National Vulnerability Database on February 10, 2011, with the most recent update on May 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2011-0539 actively exploited?
CVE-2011-0539 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2% probability of exploitation in the next 30 days, which ranks it in the top 22.4% of all scored CVEs.
What is the CVSS score of CVE-2011-0539?
CVE-2011-0539 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2011-0539?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-0539, 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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