CVE-2026-5450

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-04-20. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0

A fix is available — apply it.

Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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
Severity98% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
41%
KEV
Not listed

Published

April 20, 2026

Last Modified

July 14, 2026

Advisory Details (3)

Auto-updated Aug 29, 2026
⚠️ Active exploitation confirmed. No patch confirmed yet.
generic

34008 – (CVE-2026-5450) stdio-common: scanf %mc pattern will cause heap overflow when width > 1024

https://sourceware.org/bugzilla/show_bug.cgi?id=CVE-2026-5450
generic

The GNU C Library security advisories update for 2026-04-20

https://inbox.sourceware.org/libc-announce/[email protected]/T/#u

Patch Availability(23)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhosdt/opentelemetry-rhel9-operator:17857045472026-08-04redhat
redhatrhcos-414.92.202607210313-02026-07-31redhat
redhatrhcos-415.92.202607210244-02026-07-31redhat
redhatdiscovery/discovery-ui-rhel9:17848217502026-07-27redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatrhcos-413.92.202607141229-02026-07-23redhat
redhatrhcos-4.19.9.6.202607151909-02026-07-22redhat
redhatcostmanagement/costmanagement-metrics-rhel9-operator:17835391562026-07-15redhat
redhatcompat-glibc-1:2.12-4.el7_9.12026-07-09redhat
redhatglibc-0:2.12-1.212.el6_10.42026-07-09redhat
redhatglibc-0:2.28-151.el8_4.62026-07-08redhat
redhatinsights-proxy/insights-proxy-container-rhel9:17828905032026-07-01redhat
redhatglibc-0:2.17-326.el7_9.62026-07-01redhat
redhatglibc-0:2.39-126.el10_22026-06-30redhat
redhatglibc-0:2.39-46.el10_0.52026-06-29redhat
redhatglibc-0:2.34-272.el9_82026-06-29redhat
redhatglibc-0:2.28-225.el8_8.172026-06-29redhat
redhatglibc-0:2.34-60.el9_2.202026-06-29redhat
redhatglibc-0:2.28-189.13.el8_62026-06-29redhat
redhatglibc-0:2.28-251.el8_10.382026-06-29redhat
redhatglibc-0:2.34-168.el9_6.252026-06-29redhat
redhatglibc-0:2.34-100.el9_4.132026-06-29redhat
redhatglibc-main-2.42-12.hum12026-05-01redhat

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

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
glibc2.31-13 ... 2.43-2 (208 versions)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
glibc2.36-10~0 ... 2.43-2 (125 versions)
Debian:13(1)
PackageVulnerable rangeFixed inDependents
glibc2.41-12 ... 2.43-2 (31 versions)
Debian:14(1)
PackageVulnerable rangeFixed inDependents
glibc2.41-12 ... 2.42-9 (24 versions)2.42-17

Weakness Classification(2)

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

Additional Vendor Advisories

(6)

Data Freshness Timeline

(refreshed 6× in last 7d / 128× 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 339 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-5450?
CVE-2026-5450 is a critical vulnerability published on April 20, 2026. Calling the scanf family of functions with a %mc (malloc'd character match) in the GNU C Library version 2.7 to version 2.43 with a format width specifier with an explicit width greater than 1024 could result in a one byte heap buffer overflow.
When was CVE-2026-5450 disclosed?
CVE-2026-5450 was first published in the National Vulnerability Database on April 20, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-5450 actively exploited?
CVE-2026-5450 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 59.1% of all scored CVEs.
What is the CVSS score of CVE-2026-5450?
CVE-2026-5450 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-5450?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-5450, 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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