CVE-2026-6238

MEDIUMPre-NVD 6.56.5
EchelonGraph scoreMEDIUM confidence

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

Score 6.5 from GitHub Security Advisory published 2026-04-28. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
Trending — 4 sources updated this week
6.5EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response, causing a target application to crash or read uninitialized memory.

These functions are for application debugging only and hence not in the path of code executed by the DNS resolver. Further, they have been deprecated since version 2.34 and should not be used by any new applications. Applications should consider porting away from these interfaces since they may be removed in future versions.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
44
EG Risk 44/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity65% × 45%
Impact severity (EG Severity): CVSS 6.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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
0.4%
EPSS %ILE
37th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (6.5): severity, escalated by confirmed exploitation. This CVE's 6.5 is its impact severity (EG Severity), not escalated.

EG Severity
6.5 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-17). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

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

Exploitation none (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (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)14 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 partial (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 28, 2026

Last Modified

October 15, 2026

Advisory Details (2)

Auto-updated May 4, 2026
Patch available.
Web page

34069 – (CVE-2026-6238) Buffer overread in ns_sprintrrf with corrupted RDATA field (CVE-2026-6238)

https://sourceware.org/bugzilla/show_bug.cgi?id=34069
Web page

The GNU C Library security advisories update for 2026-04-28

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

Patch Availability(24)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntunscd (2.43-2ubuntu2.3) @ resolute2026-10-15ubuntu
redhatcert-manager/jetstack-cert-manager-rhel9:17914597112026-10-13redhat
redhatcert-manager/cert-manager-istio-csr-rhel9:17914597592026-10-13redhat
redhatcert-manager/cert-manager-operator-rhel9:17917882872026-10-13redhat
redhatcert-manager/cert-manager-operator-rhel9:17890290762026-10-13redhat
redhatcert-manager/cert-manager-istio-csr-rhel9:17913783952026-10-13redhat
redhatcert-manager/jetstack-cert-manager-rhel9:17913710692026-10-13redhat
redhatcostmanagement/costmanagement-metrics-rhel9-operator:17908443332026-10-12redhat
redhatcert-manager/cert-manager-operator-rhel9:17905898552026-09-28redhat
redhatcert-manager/jetstack-cert-manager-rhel9:17905899122026-09-28redhat
redhatcert-manager/jetstack-cert-manager-rhel9:17902232792026-09-28redhat
redhatcert-manager/cert-manager-operator-rhel9:17902724262026-09-28redhat
redhatcert-manager/cert-manager-trust-manager-rhel9:17905985932026-09-28redhat
redhatcert-manager/cert-manager-istio-csr-rhel9:17902237192026-09-28redhat
redhatcert-manager/cert-manager-istio-csr-rhel9:17905899142026-09-28redhat
redhatrhui5/rhua-tp-rhel9:17872412602026-08-24redhat
redhatinsights-proxy/insights-proxy-container-rhel9:17864336562026-08-11redhat
redhatdiscovery/discovery-server-rhel9:17848216702026-07-27redhat
redhatrhui5/rhua-rhel9:17847950762026-07-23redhat
redhatrhosdt/tempo-rhel9-operator:17847757822026-07-23redhat
redhatglibc-0:2.34-274.el9_82026-07-22redhat
redhatglibc-0:2.39-128.el10_22026-07-21redhat
redhatglibc-0:2.28-251.el8_10.402026-07-21redhat
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 ... 2.44-2 (40 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
glibc2.41-12 ... 2.43-2 (27 versions)
  • every version up to 2.43-3: fixed in 2.43-3
—

Weakness Classification(1)

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

Additional Vendor Advisories

(6)

Data Freshness Timeline

(refreshed 11× in last 7d / 34× 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 98 of 243 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. 2 repeat rows among the latest 100 are merged into the row they repeat. The 145 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-10-18 03:24 UTCEG score recompute
  4. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  5. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  6. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  7. 2026-10-15 01:47 UTCEG score recompute
  8. 2026-10-15 01:47 UTCVendor advisory
  9. 2026-10-15 01:47 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  10. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  13. 2026-10-12 15:49 UTCEG score recompute
  14. 2026-10-11 19:34 UTCEG score recompute
  15. 2026-10-11 16:49 UTCEG score recompute
  16. 2026-10-11 14:11 UTCEG score recompute
  17. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  18. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  25. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
Show 73 more
  1. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  6. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  7. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  8. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  9. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  10. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  11. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  12. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  13. 2026-09-15 03:12 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  14. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  15. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  16. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  17. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  18. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  19. 2026-09-05 15:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  20. 2026-09-04 05:07 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  21. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  22. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  23. 2026-09-01 04:40 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  24. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  25. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  26. 2026-08-28 21:42 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  27. 2026-08-26 14:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  28. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  29. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  30. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  31. 2026-08-20 22:56 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  32. 2026-08-19 17:04 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  33. 2026-08-18 13:49 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  34. 2026-08-17 13:57 UTCEG score recompute
  35. 2026-08-17 13:57 UTCVendor advisory
  36. 2026-08-17 13:57 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  37. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  38. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  39. 2026-08-16 05:28 UTCEG score recompute
  40. 2026-08-16 05:28 UTCVendor advisory
  41. 2026-08-16 05:28 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  42. 2026-08-16 02:15 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  43. 2026-08-15 01:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  44. 2026-08-14 03:56 UTCEG score recompute
  45. 2026-08-14 03:56 UTCVendor advisory
  46. 2026-08-14 03:56 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  47. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  48. 2026-08-12 23:18 UTCEG score recompute
  49. 2026-08-12 23:18 UTCVendor advisory
  50. 2026-08-12 23:18 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  51. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  52. 2026-08-12 00:37 UTCEG score recompute
  53. 2026-08-12 00:37 UTCVendor advisory
  54. 2026-08-12 00:37 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  55. 2026-08-11 01:56 UTCEG score recompute
  56. 2026-08-11 01:56 UTCVendor advisory
  57. 2026-08-11 01:56 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  58. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  59. 2026-08-10 01:48 UTCEG score recompute
  60. 2026-08-10 01:48 UTCVendor advisory
  61. 2026-08-10 01:48 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  62. 2026-08-09 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  63. 2026-08-09 03:06 UTCEG score recompute
  64. 2026-08-09 03:06 UTCVendor advisory
  65. 2026-08-09 03:06 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  66. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  67. 2026-08-07 20:06 UTCEG score recompute
  68. 2026-08-07 20:06 UTCVendor advisory
  69. 2026-08-07 20:06 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  70. 2026-08-06 21:25 UTCEG score recompute
  71. 2026-08-06 21:25 UTCVendor advisory
  72. 2026-08-06 21:25 UTCGHSA enrichmentGHSA-h8wx-jcwq-g3cp · GitHub CVSS 6.5
  73. 2026-08-06 13:47 UTCEPSS rescoreEPSS 0.4% · 28th percentile

Frequently asked(5)

What is CVE-2026-6238?
CVE-2026-6238 is a medium-severity vulnerability; its CVE record was published on April 28, 2026. The deprecated functions nsprintrrf, nsprintrr and fp_nquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response,…
When was the CVE record for CVE-2026-6238 published?
The CVE record for CVE-2026-6238 was published on April 28, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-6238 actively exploited?
CVE-2026-6238 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-6238?
CVE-2026-6238 has a CVSS v3.1 base score of 6.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-6238?
A fix for CVE-2026-6238 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-6238 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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