CVE-2021-34558

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory published 2022-05-24. NVD baseline CVSS 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Elevated
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 7%CVSS: 6.5Exploit: NoneExposed: 0

A fix is available — apply it.

The crypto/tls package of Go through 1.16.5 does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a RSA based key exchange, allowing a malicious TLS server to cause a TLS client to panic.

CVSS v3
6.5
EG Score
6.5(medium)
EPSS
93.5%
KEV
Not listed

Published

July 15, 2021

Last Modified

November 21, 2024

References (32)

Vendor Advisories for CVE-2021-34558(12)

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

Patch Availability(28)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatcontainer-tools:rhel8-8100020240227110532.828888972024-05-22redhat
redhatpodman-2:4.2.0-3.el92022-11-15redhat
redhatodf4/volume-replication-rhel8-operator:v4.10.0-112022-04-13redhat
redhatkubevirt-0:4.8.5-278.el82022-04-12redhat
redhatopenshift4-wincw/windows-machine-config-rhel8-operator:5.0.0-52022-03-28redhat
redhatgolang-github-vbatts-tar-split-0:0.11.1-6.el8ost2022-03-24redhat
redhatetcd-0:3.3.23-7.el8ost2022-01-25redhat
redhatcontainer-native-virtualization/virt-cdi-importer:v4.9.2-82022-01-19redhat
redhatodf/odf-multicluster-rhel8-operator:4.9-30.007b3d8.release_4.92021-12-13redhat
redhatmcg-0:5.9.0-28.61dcf87.5.9.el82021-12-13redhat
redhatkubevirt-0:2.6.8-211.el82021-11-17redhat
redhatstf/smart-gateway-rhel8-operator:3.0.4-12021-11-10redhat
redhatgrafana-0:7.5.9-4.el82021-11-09redhat
redhatcontainer-native-virtualization/virt-cdi-uploadserver:v4.9.0-372021-11-02redhat
redhatopenshift-sandboxed-containers-tech-preview/osc-rhel8-operator:1.1.0-32021-10-20redhat
redhatbutane-0:0.12.1-2.rhaos4.8.el82021-10-19redhat
redhatopenshift4/ose-etcd:v4.9.0-202109302317.p0.git.5c1feaf.assembly.stream2021-10-18redhat
redhatcontainer-native-virtualization/vm-import-controller-rhel8:v2.6.7-52021-10-06redhat
redhatcontainer-native-virtualization/vm-import-operator-rhel8:v4.8.2-42021-09-21redhat
redhatopenshift-serverless-1/svls-must-gather-rhel8:1.17.0-52021-09-16redhat
redhatopenshift-serverless-clients-0:0.23.2-1.el82021-09-16redhat
redhatrhmtc/openshift-velero-plugin-rhel8:v1.5.1-42021-08-31redhat
redhatgolang-github-prometheus-promu-0:0.5.0-4.git642a960.el82021-08-31redhat
redhatrosa-0:1.1.1-51c4a5e.el82021-08-26redhat
redhatdistributed-tracing/jaeger-rhel8-operator:1.20.5-52021-08-19redhat
redhatadvanced-cluster-security/rhacs-rhel8-operator:3.64.0-22021-08-12redhat
redhatignition-0:2.6.0-8.rhaos4.6.git947598e.el82021-08-12redhat
redhatredhat-release-coreos-0:47.84-1.el82021-08-11redhat

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

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.16.6—

Weakness Classification(1)

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

Additional Vendor Advisories

(23)

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

Publicly available exploits

(1 reference)

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-34558?
CVE-2021-34558 is a medium vulnerability published on July 15, 2021. The crypto/tls package of Go through 1.16.5 does not properly assert that the type of public key in an X.509 certificate matches the expected type when doing a RSA based key exchange, allowing a malicious TLS server to cause a TLS client to panic.
When was CVE-2021-34558 disclosed?
CVE-2021-34558 was first published in the National Vulnerability Database on July 15, 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-2021-34558 actively exploited?
CVE-2021-34558 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 93.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-34558?
CVE-2021-34558 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2021-34558?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-34558, 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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