CVE-2025-66564

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: 0.4% (36th 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: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type header (which is also untrusted data) on an application string. As a result, in the face of a malicious request with either an excessively long OID in the payload containing many period characters or a malformed Content-Type header, a call to api.ParseJSONRequest or api.getContentType incurs allocations of O(n) bytes (where n stands for the length of the function's argument). This vulnerability is fixed in 2.0.3.

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.
Exploitation0.4% × 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
36th
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_commit, github.
GitHub advisoryMentions a patch (unverified)

Excessive memory allocation during request parsing · Advisory · sigstore/timestamp-authority · GitHub

https://github.com/sigstore/timestamp-authority/security/advisories/GHSA-4qg8-fj49-pxjh
GitHub commit

commit 0cae34e197d6 (sigstore/timestamp-authority)

Fix landed in sigstore/timestamp-authority commit 0cae34e197d6 — awaiting tagged release

https://github.com/sigstore/timestamp-authority/commit/0cae34e197d685a14904e0bad135b89d13b69421

Vendor Advisories for CVE-2025-66564(10)

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

Patch Availability(9)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatopenshift-pipelines/pipelines-chains-controller-rhel9:17713747492026-03-05redhat
redhatopenshift-pipelines/pipelines-serve-tkn-cli-rhel9:17726794392026-03-05redhat
redhatopenshift-pipelines/pipelines-chains-controller-rhel8:17720938722026-03-04redhat
redhatrhtas/rhtas-console-rhel9:17713248652026-02-23redhat
redhatcompliance/openshift-security-profiles-rhel8-operator:17708698502026-02-17redhat
redhatadvanced-cluster-security/rhacs-rhel8-operator:17700747132026-02-11redhat
redhatadvanced-cluster-security/rhacs-rhel8-operator:17702508892026-02-09redhat
redhatrhtas/timestamp-authority-rhel9:17701074402026-02-05redhat
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

(4 across 3 ecosystems)
Go(2)
PackageVulnerable rangeFix by version rangeDependents
github.com/sigstore/timestamp-authority—
  • every version up to 2.0.3: fixed in 2.0.3
  • every version on: no fix on record
—
github.com/sigstore/timestamp-authority/v2—
  • every version up to 2.0.3: fixed in 2.0.3
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
golang-github-sigstore-timestamp-authority1.2.3-2 ... 2.1.3-2 (9 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
golang-github-sigstore-timestamp-authority1.2.3-2, 1.2.9-1
  • every version up to 2.0.3-1: fixed in 2.0.3-1
—

Weakness Classification(1)

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

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 171 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 80 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 0.4% · 36th percentile
  2. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-12 16:48 UTCEG score recompute
  5. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.4% · 36th 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 0.4% · 36th percentile
  10. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  13. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  14. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  15. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  16. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  17. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  18. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-01 06:40 UTCOSV refresh
  20. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-09-28 13:50 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  24. 2026-09-24 14:02 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-09-23 13:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
Show 66 more
  1. 2026-09-20 20:15 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-09-19 15:42 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  4. 2026-09-17 19:30 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  5. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  6. 2026-09-15 03:10 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  7. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  8. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  9. 2026-09-12 07:53 UTCOSV refresh
  10. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  11. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  12. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  13. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  14. 2026-09-07 16:00 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  15. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  16. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  17. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-08-30 19:16 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-08-30 01:21 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  21. 2026-08-28 21:40 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  22. 2026-08-27 14:24 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  23. 2026-08-26 14:45 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  24. 2026-08-25 13:48 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  25. 2026-08-24 14:16 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  26. 2026-08-24 13:02 UTCOSV refresh
  27. 2026-08-23 00:18 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  28. 2026-08-21 23:48 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  29. 2026-08-20 22:55 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  30. 2026-08-19 17:03 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  31. 2026-08-18 13:47 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  32. 2026-08-17 13:46 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  33. 2026-08-16 14:55 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  34. 2026-08-16 02:13 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  35. 2026-08-15 01:29 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  36. 2026-08-13 21:59 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  37. 2026-08-12 13:50 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  38. 2026-08-11 13:42 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  39. 2026-08-10 23:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  40. 2026-08-09 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  41. 2026-08-08 16:36 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  42. 2026-08-08 08:34 UTCEG score recompute
  43. 2026-08-08 08:34 UTCVendor advisory
  44. 2026-08-07 16:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  45. 2026-08-06 13:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  46. 2026-08-05 19:17 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  47. 2026-08-04 15:09 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  48. 2026-08-04 10:37 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  49. 2026-08-03 10:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  50. 2026-08-02 02:26 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  51. 2026-08-01 04:15 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  52. 2026-07-30 16:27 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  53. 2026-07-30 01:30 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  54. 2026-07-28 15:35 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  55. 2026-07-27 14:12 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  56. 2026-07-26 14:54 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  57. 2026-07-25 14:17 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  58. 2026-07-24 14:17 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  59. 2026-07-23 14:18 UTCEPSS rescoreEPSS 0.4% · 34th 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 0.4% · 33rd percentile
  63. 2026-07-21 15:24 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  64. 2026-07-20 17:08 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  65. 2026-07-19 02:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  66. 2026-07-18 10:04 UTCEPSS rescoreEPSS 0.4% · 33rd percentile

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

Same product

2 shown

Debian:13:golang-github-sigstore-timestamp-authority

Frequently asked(5)

What is CVE-2025-66564?
CVE-2025-66564 is a high-severity vulnerability; its CVE record was published on December 4, 2025. Sigstore Timestamp Authority is a service for issuing RFC 3161 timestamps. Prior to 2.0.3, Function api.ParseJSONRequest currently splits (via a call to strings.Split) an optionally-provided OID (which is untrusted data) on periods. Similarly, function api.getContentType splits the Content-Type…
When was the CVE record for CVE-2025-66564 published?
The CVE record for CVE-2025-66564 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-2025-66564 actively exploited?
CVE-2025-66564 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2025-66564?
CVE-2025-66564 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-2025-66564?
A fix for CVE-2025-66564 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2025-66564 are linked in the Vendor Advisories panel on this page.

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