CVE-2026-5450

CRITICALPre-NVD 9.89.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

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 (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 5 sources updated this weekElevated
9.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.7%CVSS: 9.8Exploit: No code on recordExposed services: Not assessed

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
9.8CRITICALmedium confidence
EG Risk
75
EG Risk 75/100

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 (value × EchelonGraph’s weight)
Severity98% × 45%
The EG Score, 9.8 of 10.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.7%
EPSS %ILE
52nd
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)3 days if the affected system is publicly exposed; 60 days if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

April 20, 2026

Last Modified

July 14, 2026

Advisory Details (3)

Auto-updated Oct 11, 2026
Patch available.
Web page

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
Web page

SSA-082556

https://cert-portal.siemens.com/productcert/html/ssa-082556.html
Web page

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

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

Vendor Advisories for CVE-2026-5450(20)

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

Patch Availability(30)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatrhai/base-image-neuron-rhel9:17907035422026-10-01redhat
redhatcert-manager/cert-manager-trust-manager-rhel9:17905985932026-09-28redhat
redhatopenshift/ose-rhel-coreos-8:412.86.202608241157-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-9:417.94.202608250221-02026-09-03redhat
redhatopenshift/ose-rhel-coreos-9:416.94.202608150307-02026-08-31redhat
redhatopenshift/ose-rhel-coreos-9:418.94.202608142238-02026-08-26redhat
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
redhatrhosdt/opentelemetry-rhel9-operator:17857045472026-08-04redhat
redhatopenshift/ose-rhel-coreos-9:415.92.202607210244-02026-07-31redhat
redhatopenshift/ose-rhel-coreos-9:414.92.202607210313-02026-07-31redhat
redhatdiscovery/discovery-ui-rhel9:17848217502026-07-27redhat
redhatopenshift/ose-rhel-coreos-9:413.92.202607141229-02026-07-23redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatopenshift/ose-rhel-coreos-9:4.19.9.6.202607151909-02026-07-22redhat
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
redhatglibc-0:2.17-326.el7_9.62026-07-01redhat
redhatinsights-proxy/insights-proxy-container-rhel9:17828905032026-07-01redhat
redhatglibc-0:2.39-126.el10_22026-06-30redhat
redhatglibc-0:2.34-168.el9_6.252026-06-29redhat
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-0:2.39-46.el10_0.52026-06-29redhat
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 rangeFix by version rangeDependents
glibc2.31-13 ... 2.43-2 (208 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
glibc2.36-10~0 ... 2.44-2 (134 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
glibc2.41-12, 2.41-12+deb13u1, 2.41-12+deb13u2, 2.41-12+deb13u3
  • every version up to 2.41-12+deb13u4: fixed in 2.41-12+deb13u4
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
glibc2.41-12 ... 2.42-9 (24 versions)
  • every version up to 2.42-17: fixed in 2.42-17
—

Weakness Classification(2)

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

Additional Vendor Advisories

(16)

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 21× in last 7d / 39× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

Showing the most recent 100 of 389 refreshes on record for this CVE.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. None are among the latest 100 rows. The 289 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  2. 2026-10-14 09:11 UTCEG score recompute
  3. 2026-10-14 09:11 UTCVendor advisory
  4. 2026-10-14 09:10 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  5. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  6. 2026-10-13 06:16 UTCEG score recompute
  7. 2026-10-13 06:16 UTCVendor advisory
  8. 2026-10-13 06:16 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  10. 2026-10-12 15:56 UTCEG score recompute
  11. 2026-10-12 06:56 UTCVendor advisory
  12. 2026-10-12 06:56 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  13. 2026-10-11 19:39 UTCEG score recompute
  14. 2026-10-11 16:54 UTCEG score recompute
  15. 2026-10-11 14:18 UTCEG score recompute
  16. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  17. 2026-10-11 05:25 UTCOSV refresh
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  19. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  20. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  21. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  25. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
Show 75 more
  1. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  2. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.7% · 52nd percentile
  4. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  5. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  6. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.7% · 51st percentile
  7. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-09-21 17:19 UTCOSV refresh
  9. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  10. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  11. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  13. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  14. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  15. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  16. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  17. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  18. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  19. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  21. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  23. 2026-09-02 14:01 UTCOSV refresh
  24. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  25. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  26. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  27. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  28. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  29. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  30. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  31. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  32. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  33. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  34. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  35. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  36. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  37. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  38. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  39. 2026-08-16 10:15 UTCVendor advisory
  40. 2026-08-16 10:15 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  41. 2026-08-16 06:22 UTCEG score recompute
  42. 2026-08-16 06:22 UTCVendor advisory
  43. 2026-08-16 06:22 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  44. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  45. 2026-08-14 23:55 UTCVendor advisory
  46. 2026-08-14 23:55 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  47. 2026-08-14 20:02 UTCVendor advisory
  48. 2026-08-14 20:02 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  49. 2026-08-14 16:10 UTCVendor advisory
  50. 2026-08-14 16:10 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  51. 2026-08-14 12:17 UTCVendor advisory
  52. 2026-08-14 12:17 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  53. 2026-08-14 08:25 UTCVendor advisory
  54. 2026-08-14 08:25 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  55. 2026-08-14 04:32 UTCEG score recompute
  56. 2026-08-14 04:32 UTCVendor advisory
  57. 2026-08-14 04:32 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  58. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  59. 2026-08-13 08:48 UTCVendor advisory
  60. 2026-08-13 08:48 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  61. 2026-08-13 02:28 UTCVendor advisory
  62. 2026-08-13 02:28 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  63. 2026-08-12 22:35 UTCVendor advisory
  64. 2026-08-12 22:35 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  65. 2026-08-12 18:43 UTCEG score recompute
  66. 2026-08-12 18:43 UTCVendor advisory
  67. 2026-08-12 18:43 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  68. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  69. 2026-08-12 00:39 UTCVendor advisory
  70. 2026-08-12 00:38 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  71. 2026-08-11 20:46 UTCVendor advisory
  72. 2026-08-11 20:46 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8
  73. 2026-08-11 16:53 UTCEG score recompute
  74. 2026-08-11 16:53 UTCVendor advisory
  75. 2026-08-11 16:53 UTCGHSA enrichmentGHSA-v898-xg3c-w4rj · GitHub severity CRITICAL · GitHub CVSS 9.8

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-5450?
CVE-2026-5450 is a critical-severity vulnerability; its CVE record was 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 made public?
CVE-2026-5450 was made public on March 19, 2026: that is the date its CVE record's CNA, GNU C Library, gives for when the vulnerability was made public. The CVE record itself was published on April 20, 2026. EchelonGraph's copy of the record carries a last-modified date of July 14, 2026; the record at its source may have been updated since.
Is CVE-2026-5450 actively exploited?
CVE-2026-5450 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.7% probability of exploitation in the next 30 days (52nd percentile of EPSS-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?
A fix for CVE-2026-5450 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-5450 are linked in the Vendor Advisories panel on this page.

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