CVE-2021-3516

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 2.0%, top 21% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 2%CVSS: 7.8Exploit: None knownExposed: 0

A fix is available — apply it.

There's a flaw in libxml2's xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability.

CVSS v3
7.8
EG Score
7.8(medium)
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
Severity78% × 45%
Exploitation2% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
2%
EPSS %ILE
79%
KEV
Not listed

Published

June 1, 2021

Last Modified

November 21, 2024

References (18)

Vendor Advisories for CVE-2021-3516(4)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatjbcs-httpd24-openssl-pkcs11-0:0.4.10-26.jbcs.el72022-04-20redhat
redhatlibxml22022-04-20redhat
redhatrhmtc/openshift-velero-plugin-rhel8:v1.4.6-42021-07-21redhat
redhatlibxml2-0:2.9.7-9.el8_4.22021-06-29redhat

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.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
libxml2—2.9.10+dfsg-6.6—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
libxml2—2.9.10+dfsg-6.6—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
libxml2—2.9.10+dfsg-6.6—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
libxml2—2.9.10+dfsg-6.6—
Debian:9(1)
PackageVulnerable rangeFixed inDependents
libxml22.9.4+dfsg1-2.2, 2.9.4+dfsg1-2.2+deb9u1, 2.9.4+dfsg1-2.2+deb9u2, 2.9.4+dfsg1-2.2+deb9u32.9.4+dfsg1-2.2+deb9u4—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 9× in last 7d / 31× 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 136 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2021-3516?
CVE-2021-3516 is a high vulnerability published on June 1, 2021. There's a flaw in libxml2's xmllint in versions before 2.9.11. An attacker who is able to submit a crafted file to be processed by xmllint could trigger a use-after-free. The greatest impact of this flaw is to confidentiality, integrity, and availability.
When was CVE-2021-3516 disclosed?
CVE-2021-3516 was first published in the National Vulnerability Database on June 1, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-3516 actively exploited?
CVE-2021-3516 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 20.9% of all scored CVEs.
What is the CVSS score of CVE-2021-3516?
CVE-2021-3516 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-3516?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-3516, 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

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