CVE-2025-66506

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (10th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
7.5EG
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).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a malicious request with an (invalid) OIDC identity token in the payload containing many period characters, a call to extractIssuerURL incurs allocations to the tune of O(n) bytes (where n stands for the length of the function's argument), with a constant factor of about 16. This vulnerability is fixed in 1.8.3.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
49
EG Risk 49/100

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)
Severity75% × 45%
The EG Score, 7.5 of 10.
Exploitation0.2% × 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
0.2%
EPSS %ILE
10th
KEV
Not listed

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

December 4, 2025

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Aug 8, 2026
Patch available. Sources: github, github_commit.
GitHub advisoryMentions a patch (unverified)

Excessive memory allocation during token parsing · Advisory · sigstore/fulcio · GitHub

https://github.com/sigstore/fulcio/security/advisories/GHSA-f83f-xpx7-ffpw
GitHub commit

commit 765a0e57608b (sigstore/fulcio)

Fix landed in sigstore/fulcio commit 765a0e57608b — awaiting tagged release

https://github.com/sigstore/fulcio/commit/765a0e57608b9ef390e1eeeea8595b9054c63a5a

Vendor Advisories for CVE-2025-66506(20)

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

Patch Availability(29)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatoadp/oadp-velero-plugin-rhel9:17851773572026-08-06redhat
redhatrhmtc/openshift-migration-controller-rhel8:17839533722026-07-20redhat
redhatodf4/rook-ceph-rhel9-operator:17829342842026-07-09redhat
redhatopenshift-pipelines/pipelines-cli-tkn-rhel9:17742626332026-03-30redhat
redhatopenshift-pipelines/pipelines-operator-bundle:17748713902026-03-30redhat
redhatquay/quay-rhel8:17730976212026-03-10redhat
redhatquay/quay-rhel8:17730888622026-03-10redhat
redhatopenshift-pipelines/pipelines-cli-tkn-rhel9:17726948652026-03-05redhat
redhatopenshift-pipelines/pipelines-chains-controller-rhel9:17713747492026-03-05redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17718741812026-03-04redhat
redhatopenshift-pipelines/pipelines-chains-controller-rhel8:17720938722026-03-04redhat
redhatopenshift-pipelines/pipelines-rhel8-operator:17721227542026-03-04redhat
redhatrhaiis/vllm-cuda-rhel9:17721605932026-02-27redhat
redhatrhaiis/vllm-rocm-rhel9:17721606252026-02-27redhat
redhatrhtas/client-server-rhel9:17707897922026-02-18redhat
redhatrhtas/gitsign-rhel9:17707342832026-02-18redhat
redhatnetwork-observability/network-observability-cli-rhel9:17712260602026-02-18redhat
redhatcompliance/openshift-security-profiles-rhel8-operator:17708698502026-02-17redhat
redhatquay/quay-rhel8:17702491832026-02-16redhat
redhatquay/quay-rhel8:17708561032026-02-16redhat
redhatrhoai/odh-model-registry-job-async-upload-rhel9:17703588472026-02-12redhat
redhatadvanced-cluster-security/rhacs-scanner-v4-rhel8:17700747132026-02-11redhat
redhatadvanced-cluster-security/rhacs-scanner-v4-rhel8:17702508892026-02-09redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17700554252026-02-05redhat
redhatrhtas/gitsign-rhel9:17701081932026-02-05redhat
redhatrhtas/fulcio-rhel9:17701074462026-02-05redhat
redhatquay/quay-rhel8:17701465652026-02-04redhat
redhatquay/quay-rhel8:17698520132026-02-02redhat
redhatadvanced-cluster-security/rhacs-main-rhel8:17696156592026-01-28redhat

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

(3 across 3 ecosystems)
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
golang-github-sigstore-fulcio1.6.5-1, 1.7.1-1, 1.8.5-1, 1.8.7-1, 1.8.8-1
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
golang-github-sigstore-fulcio1.6.5-1, 1.7.1-1
  • every version up to 1.8.5-1: fixed in 1.8.5-1
—
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/sigstore/fulcio—
  • every version up to 1.8.3: fixed in 1.8.3
—

Weakness Classification(1)

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 11× in last 7d / 30× 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 91 of 172 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. 9 repeat rows among the latest 100 are merged into the row they repeat. The 81 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  2. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  3. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  4. 2026-10-12 16:48 UTCEG score recompute
  5. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  6. 2026-10-11 20:23 UTCEG score recompute
  7. 2026-10-11 18:35 UTCEG score recompute
  8. 2026-10-11 15:09 UTCEG score recompute
  9. 2026-10-11 13:47 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  10. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  11. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  12. 2026-10-08 17:10 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  13. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  14. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  15. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  16. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  17. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  18. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  19. 2026-10-01 06:40 UTCOSV refresh
  20. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  21. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  22. 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  23. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  24. 2026-09-24 14:02 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  25. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
Show 66 more
  1. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  2. 2026-09-19 15:42 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  3. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  4. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  5. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  6. 2026-09-15 03:10 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  7. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  8. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  9. 2026-09-12 07:53 UTCOSV refresh
  10. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  11. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  12. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  13. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  14. 2026-09-07 16:00 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  15. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  16. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  17. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  18. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  19. 2026-08-30 19:16 UTCEPSS rescoreEPSS 0.2% · 11th percentile
  20. 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  21. 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  22. 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  23. 2026-08-26 14:45 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  24. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  25. 2026-08-24 14:16 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  26. 2026-08-24 13:02 UTCOSV refresh
  27. 2026-08-23 00:18 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  28. 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  29. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  30. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  31. 2026-08-18 13:47 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  32. 2026-08-17 13:46 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  33. 2026-08-16 14:55 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  34. 2026-08-16 02:13 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  35. 2026-08-15 01:29 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  36. 2026-08-13 21:59 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  37. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  38. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  39. 2026-08-10 23:59 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  40. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  41. 2026-08-08 16:36 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  42. 2026-08-08 08:35 UTCEG score recompute
  43. 2026-08-08 08:35 UTCVendor advisory
  44. 2026-08-07 16:26 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  45. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  46. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  47. 2026-08-04 15:09 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  48. 2026-08-04 10:37 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  49. 2026-08-03 10:35 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  50. 2026-08-02 02:26 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  51. 2026-08-01 04:15 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  52. 2026-07-30 16:27 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  53. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  54. 2026-07-28 15:35 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  55. 2026-07-27 14:12 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  56. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.2% · 9th percentile
  57. 2026-07-25 14:17 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  58. 2026-07-24 14:17 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  59. 2026-07-23 14:18 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  60. 2026-07-23 13:49 UTCOSV refresh
  61. 2026-07-23 03:01 UTCEG score recompute
  62. 2026-07-22 14:08 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  63. 2026-07-21 15:24 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  64. 2026-07-20 17:08 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  65. 2026-07-19 14:30 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  66. 2026-07-19 02:28 UTCEPSS rescoreEPSS 0.2% · 8th percentile

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

Same product

2 shown

Debian:13:golang-github-sigstore-fulcio

Frequently asked(5)

What is CVE-2025-66506?
CVE-2025-66506 is a high-severity vulnerability; its CVE record was published on December 4, 2025. Fulcio is a free-to-use certificate authority for issuing code signing certificates for an OpenID Connect (OIDC) identity. Prior to 1.8.3, function identity.extractIssuerURL splits (via a call to strings.Split) its argument (which is untrusted data) on periods. As a result, in the face of a…
When was the CVE record for CVE-2025-66506 published?
The CVE record for CVE-2025-66506 was published on December 4, 2025. 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 June 17, 2026; the record at its source may have been updated since.
Is CVE-2025-66506 actively exploited?
CVE-2025-66506 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2025-66506?
CVE-2025-66506 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2025-66506?
A fix for CVE-2025-66506 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2025-66506 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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