CVE-2026-40510

MEDIUMNVD 6.86.8
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.8 under NVD CVSS v3. EPSS exploit probability: 0.3% (15th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 3.8 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-05-29) is not newer than that change (2026-07-21), so it does not.

Triggered by: Headline CVSS from NVD CVSS v3
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3
6.8EG
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: 0.3%CVSS: 6.8Exploit: None knownExposed services: Not assessed

An upstream fix is merged but not yet released — mitigate (WAF / firewall / segmentation) until the release ships, then apply it.

OpenSC before 0.27.0-rc1, fixed in commit 3f24f0b, contains a stack buffer overflow vulnerability in piv_process_history() in src/libopensc/card-piv.c that allows physically present attackers to trigger memory corruption by presenting a crafted PIV smart card or USB device returning a URL field longer than 118 bytes in the Key History Object ASN.1 response.

CVSS v3
6.8
EG Score
6.8MEDIUMmedium confidence
EG Risk
31
EG Risk 31/100

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)
Severity68% × 45%
Impact severity (EG Severity): CVSS 6.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 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: An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.
EPSS PROB
0.3%
EPSS %ILE
15th
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 (6.8): severity, escalated by confirmed exploitation. This CVE's 6.8 is its impact severity (EG Severity), not escalated.

EG Severity
6.8 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.3% 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 every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade 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 every mission impact level.

An upstream fix is merged but not yet in a tagged release. Restrict network exposure of the affected system or apply the vendor's mitigation within your standard update timelines until it ships, then apply the release.

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

May 29, 2026

Last Modified

July 21, 2026

Advisory Details (3)

Auto-updated Jun 13, 2026
Upstream fix merged — awaiting tagged release. Sources: github_pr, github_commit.
Web page

OpenSC < 0.27.0-rc1 Stack Buffer Overflow via piv_process_history() in card-piv.c | Advisories | VulnCheck

https://www.vulncheck.com/advisories/opensc-stack-buffer-overflow-via-piv-process-history-in-card-piv-c
GitHub pull request

card-piv.c - fix history object

Fix merged in OpenSC/OpenSC PR #3558 on 2026-01-26 — awaiting tagged release

https://github.com/OpenSC/OpenSC/pull/3558
GitHub commit

commit 3f24f0b48a48 (OpenSC/OpenSC)

Fix landed in OpenSC/OpenSC commit 3f24f0b48a48 — awaiting tagged release

https://github.com/OpenSC/OpenSC/commit/3f24f0b48a481a8cf2e46059d8238a283ddc1c13

Vendor Advisories for CVE-2026-40510(2)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 29× 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 99 of 214 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. 1 repeat row among the latest 100 is merged into the row it repeats. The 115 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 0.3% · 15th percentile
  2. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  3. 2026-10-18 03:42 UTCEG score recompute
  4. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  5. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  6. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  7. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  8. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  9. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  10. 2026-10-12 16:09 UTCEG score recompute
  11. 2026-10-11 19:51 UTCEG score recompute
  12. 2026-10-11 17:05 UTCEG score recompute
  13. 2026-10-11 14:31 UTCEG score recompute
  14. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  15. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  16. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  17. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  18. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  19. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  20. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  21. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  22. 2026-10-03 14:48 UTCOSV refresh
  23. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  24. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  25. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 15th percentile
Show 74 more
  1. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  2. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  3. 2026-09-23 17:53 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  4. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  5. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  6. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  7. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  8. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  9. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-09-14 06:27 UTCEG score recompute
  11. 2026-09-14 06:27 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  12. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-09-13 02:09 UTCOSV refresh
  14. 2026-09-12 15:01 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  15. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  16. 2026-09-11 09:37 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  17. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  18. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  19. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  20. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  21. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  22. 2026-09-02 14:12 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  23. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  24. 2026-08-30 19:17 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  25. 2026-08-30 01:22 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  26. 2026-08-28 21:41 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  27. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  28. 2026-08-26 14:46 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  29. 2026-08-25 13:49 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  30. 2026-08-25 04:27 UTCEG score recompute
  31. 2026-08-25 04:27 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  32. 2026-08-23 14:17 UTCEG score recompute
  33. 2026-08-23 14:16 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  34. 2026-08-23 00:19 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  35. 2026-08-21 23:49 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  36. 2026-08-21 15:12 UTCEG score recompute
  37. 2026-08-21 15:12 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  38. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  39. 2026-08-20 10:28 UTCEG score recompute
  40. 2026-08-20 10:28 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  41. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  42. 2026-08-18 13:48 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  43. 2026-08-17 13:47 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  44. 2026-08-17 06:54 UTCEG score recompute
  45. 2026-08-17 06:54 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  46. 2026-08-16 14:56 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  47. 2026-08-16 02:25 UTCEG score recompute
  48. 2026-08-16 02:25 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  49. 2026-08-16 02:14 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  50. 2026-08-15 01:30 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  51. 2026-08-15 00:01 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  52. 2026-08-14 00:37 UTCEG score recompute
  53. 2026-08-14 00:37 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  54. 2026-08-13 22:00 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  55. 2026-08-12 22:45 UTCEG score recompute
  56. 2026-08-12 22:45 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  57. 2026-08-12 13:51 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  58. 2026-08-11 23:21 UTCEG score recompute
  59. 2026-08-11 23:21 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  60. 2026-08-11 13:43 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  61. 2026-08-11 00:00 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  62. 2026-08-10 23:58 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  63. 2026-08-09 20:16 UTCEG score recompute
  64. 2026-08-09 20:16 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  65. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  66. 2026-08-08 20:52 UTCEG score recompute
  67. 2026-08-08 20:52 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  68. 2026-08-08 16:37 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  69. 2026-08-07 21:27 UTCEG score recompute
  70. 2026-08-07 21:27 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  71. 2026-08-06 22:04 UTCEG score recompute
  72. 2026-08-06 22:03 UTCGHSA enrichmentGHSA-7rrw-cv3r-3cgg · GitHub severity LOW · GitHub CVSS 3.8
  73. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.2% · 12th percentile
  74. 2026-08-05 22:39 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-40510?
CVE-2026-40510 is a medium-severity vulnerability; its CVE record was published on May 29, 2026. OpenSC before 0.27.0-rc1, fixed in commit 3f24f0b, contains a stack buffer overflow vulnerability in pivprocesshistory() in src/libopensc/card-piv.c that allows physically present attackers to trigger memory corruption by presenting a crafted PIV smart card or USB device returning a URL field…
When was CVE-2026-40510 made public?
CVE-2026-40510 was made public on January 26, 2026: that is the date its CVE record's CNA, VulnCheck, gives for when the vulnerability was made public. The CVE record itself was published on May 29, 2026. EchelonGraph's copy of the record carries a last-modified date of July 21, 2026; the record at its source may have been updated since.
Is CVE-2026-40510 actively exploited?
CVE-2026-40510 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-40510?
CVE-2026-40510 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-40510?
An upstream fix for CVE-2026-40510 has been merged but is not yet in a tagged release. Until it ships, restrict network exposure of the affected system or apply the vendor's mitigation, then update to the release that contains the fix. The vendor advisories EchelonGraph has for CVE-2026-40510 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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