CVE-2026-42494

MEDIUMPre-NVD 6.16.1
EchelonGraph scoreMEDIUM confidence

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

Score 6.1 from GitHub Security Advisory published 2026-07-28. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 6.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS, GitHub Security Advisory
6.1EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.1%CVSS: 6.1Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.]

The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver derives several lengths directly from attacker-controlled on-disk fields without validating them:

* The directory loop itself assumes a good record length. This is CVE-2026-42494.

* The calculation of the System Use area may underflow. This is CVE-2026-42495.

* The Rock Ridge extension loop assumes a good (inner) record length. This is CVE-2026-62423.

* The Rock Ridge NM record processing assumes a good entry length. This is CVE-2026-62424.

* The Rock Ridge CE record processing assumes a good size and offset. This is CVE-2026-62425.

CVSS v3
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100

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)
Severity61% × 45%
The EG Score, 6.1 of 10.
Exploitation0.1% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (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.
EPSS PROB
0.1%
EPSS %ILE
1st
KEV
Not listed

SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (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

July 28, 2026

Last Modified

July 28, 2026

Advisory Details (1)

Auto-updated Jul 28, 2026
Patch available.
Web page

XSA-497 - Xen Security Advisories

https://xenbits.xenproject.org/xsa/advisory-497.html

Vendor Advisories for CVE-2026-42494(1)

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

Affected Packages

(8 across 8 ecosystems)
Alpine:v3.21(1)
PackageVulnerable rangeFix by version rangeDependents
xen—
  • every version up to 4.19.6-r0: fixed in 4.19.6-r0
—
Alpine:v3.22(1)
PackageVulnerable rangeFix by version rangeDependents
xen—
  • every version up to 4.20.4-r0: fixed in 4.20.4-r0
—
Alpine:v3.23(1)
PackageVulnerable rangeFix by version rangeDependents
xen—
  • every version up to 4.20.4-r0: fixed in 4.20.4-r0
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
xen—
  • every version up to 4.21.2-r0: fixed in 4.21.2-r0
—
Debian:11(1)
PackageVulnerable rangeFix by version rangeDependents
xen4.14.2+25-gb6a8c4f72d-2 ... 4.20.3+127-gc42374a105-1 (46 versions)
  • every version on: no fix on record
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
xen4.17.1+2-gb773c48e36-1 ... 4.17.5+72-g01140da4e8-1 (14 versions)
  • every version up to 4.17.7-0+deb12u1: fixed in 4.17.7-0+deb12u1
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
xen4.20.0+68-g35cb38b222-1 ... 4.20.2+7-g1badcf5035-2 (6 versions)
  • every version up to 4.20.3+127-gc42374a105-0+deb13u1: fixed in 4.20.3+127-gc42374a105-0+deb13u1
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
xen4.20.0+68-g35cb38b222-1, 4.20.2+37-g61ff35323e-1, 4.20.2+7-g1badcf5035-1, 4.20.2+7-g1badcf5035-2
  • every version up to 4.20.3+127-gc42374a105-1: fixed in 4.20.3+127-gc42374a105-1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 50× 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 173 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 73 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  3. 2026-10-12 16:07 UTCEG score recompute
  4. 2026-10-11 19:49 UTCEG score recompute
  5. 2026-10-11 17:03 UTCEG score recompute
  6. 2026-10-11 14:29 UTCEG score recompute
  7. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-10-07 00:06 UTCEG score recompute
  13. 2026-10-07 00:06 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  14. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  15. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  16. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  17. 2026-10-04 07:11 UTCEG score recompute
  18. 2026-10-04 07:11 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  19. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  20. 2026-10-02 18:24 UTCEG score recompute
  21. 2026-10-02 18:24 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  22. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  23. 2026-10-01 03:44 UTCEG score recompute
  24. 2026-10-01 03:44 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  25. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
Show 75 more
  1. 2026-09-29 07:47 UTCEG score recompute
  2. 2026-09-29 07:47 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  3. 2026-09-28 03:25 UTCEG score recompute
  4. 2026-09-28 03:25 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  5. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  6. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 3rd percentile
  7. 2026-09-25 06:17 UTCEG score recompute
  8. 2026-09-25 06:17 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  9. 2026-09-23 21:56 UTCEG score recompute
  10. 2026-09-23 21:56 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  11. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  12. 2026-09-22 21:43 UTCEG score recompute
  13. 2026-09-22 21:43 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  14. 2026-09-20 05:41 UTCEG score recompute
  15. 2026-09-20 05:41 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  16. 2026-09-19 05:18 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  17. 2026-09-18 02:09 UTCEG score recompute
  18. 2026-09-18 02:09 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  19. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  20. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  21. 2026-09-16 11:51 UTCEG score recompute
  22. 2026-09-16 11:51 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  23. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  24. 2026-09-15 08:51 UTCEG score recompute
  25. 2026-09-15 08:51 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  26. 2026-09-14 06:46 UTCEG score recompute
  27. 2026-09-14 06:46 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  28. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  29. 2026-09-13 07:02 UTCEG score recompute
  30. 2026-09-13 07:02 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  31. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  32. 2026-09-12 07:18 UTCEG score recompute
  33. 2026-09-12 07:18 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  34. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  35. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  36. 2026-09-11 07:33 UTCEG score recompute
  37. 2026-09-11 07:33 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  38. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  39. 2026-09-10 07:49 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  40. 2026-09-09 08:04 UTCEG score recompute
  41. 2026-09-09 08:04 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  42. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  43. 2026-09-07 20:56 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  44. 2026-09-06 18:55 UTCEG score recompute
  45. 2026-09-06 18:55 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  46. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  47. 2026-09-05 19:10 UTCEG score recompute
  48. 2026-09-05 19:10 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  49. 2026-09-04 12:04 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  50. 2026-09-02 00:51 UTCEG score recompute
  51. 2026-09-02 00:51 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  52. 2026-09-01 13:54 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  53. 2026-09-01 00:48 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  54. 2026-08-30 23:20 UTCEG score recompute
  55. 2026-08-30 23:20 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  56. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  57. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  58. 2026-08-29 23:35 UTCEG score recompute
  59. 2026-08-29 23:35 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  60. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  61. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  62. 2026-08-27 09:37 UTCEG score recompute
  63. 2026-08-27 09:37 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  64. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  65. 2026-08-26 08:56 UTCEG score recompute
  66. 2026-08-26 08:56 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  67. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  68. 2026-08-25 09:11 UTCEG score recompute
  69. 2026-08-25 09:11 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  70. 2026-08-24 09:27 UTCEG score recompute
  71. 2026-08-24 09:27 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  72. 2026-08-23 09:42 UTCEG score recompute
  73. 2026-08-23 09:42 UTCGHSA enrichmentGHSA-q84c-p45w-7mv4 · GitHub CVSS 6.1
  74. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.1% · 1st percentile
  75. 2026-08-22 09:58 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-42494?
CVE-2026-42494 is a medium-severity vulnerability; its CVE record was published on July 28, 2026. [This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] The directory and Rock Ridge / SUSP walk in libfsimage's iso9660 driver derives several lengths directly from attacker-controlled on-disk fields without validating them:…
When was CVE-2026-42494 made public?
CVE-2026-42494 was made public on July 28, 2026: that is the date its CVE record's CNA, Xen Project, gives for when the vulnerability was made public. The CVE record itself was published on July 28, 2026. EchelonGraph's copy of the record carries a last-modified date of July 28, 2026; the record at its source may have been updated since.
Is CVE-2026-42494 actively exploited?
CVE-2026-42494 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.1% probability of exploitation in the next 30 days (1st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-42494?
CVE-2026-42494 has a CVSS v3.1 base score of 6.1 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42494?
A fix for CVE-2026-42494 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-42494 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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