CVE-2025-12642

CRITICALNVD 9.19.1
EchelonGraph scoreMEDIUM confidence

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

Score 9.1 from GitHub Security Advisory (severity: MODERATE) published 2025-11-03. NVD baseline CVSS 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2025-37517 (ENISA EUVD) · GHSA-fvx8-q97q-cw73 (GitHub Security Advisories)Source: ENISA EUVD

9.1EG
EchelonGraph verdictPlan mitigationThe upstream fix is not in a release yet: until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 9.1Exploit: 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.

lighttpd1.4.80 incorrectly merged trailer fields into headers after http request parsing. This behavior can be exploited to conduct HTTP Header Smuggling attacks.

Successful exploitation may allow an attacker to:

* Bypass access control rules * Inject unsafe input into backend logic that trusts request headers * Execute HTTP Request Smuggling attacks under some conditions

This issue affects lighttpd1.4.80

CVSS v3
9.1
EG Score
9.1CRITICALmedium confidence
EG Risk
56
EG Risk 56/100

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)
Severity91% × 45%
Impact severity (EG Severity): CVSS 9.1 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: An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.
EPSS PROB
0.4%
EPSS %ILE
31st
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 (9.1): severity, escalated by confirmed exploitation. This CVE's 9.1 is its impact severity (EG Severity), not escalated.

EG Severity
9.1 CRITICALCVSS-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 2026-11-12). 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.No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.Each input and its source, and whom BOD 26-04 binds: 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).

An upstream fix is merged but not yet in a tagged release. Until the release ships, restrict network exposure of the affected system or apply the vendor's mitigation on your normal schedule at low or medium mission impact and sooner than that at high, then apply it.

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.

No released fix is confirmed on this page, but CISA's timeline does not wait for a fix's release: it starts when an agency identifies the flaw on an asset and updates the CDM Agency and Federal Dashboard, and the directive counts patching, decommissioning the system or another action as remediation. Until a fixed release is applied, mitigate as this page's verdict says.

The score's inputs: 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

November 3, 2025

Last Modified

October 19, 2026

Advisory Details (1)

Auto-updated Aug 1, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
GitHub commit

commit 35cb89c10387 (lighttpd/lighttpd1.4)

Fix landed in lighttpd/lighttpd1.4 commit 35cb89c10387 — awaiting tagged release

https://github.com/lighttpd/lighttpd1.4/commit/35cb89c103877de62d6b63d0804255475d77e5e1

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 15× in last 7d / 61× 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 its CVE.org record (CNA or CISA ADP). 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). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 268 rows 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 168 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:49 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  2. 2026-11-13 13:48 UTCEchelonGraph re-scored
  3. 2026-11-13 13:48 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  4. 2026-11-12 16:32 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  5. 2026-11-12 14:46 UTCEchelonGraph re-scored
  6. 2026-11-12 14:46 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  7. 2026-11-11 16:35 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  8. 2026-11-11 15:45 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  9. 2026-11-10 16:45 UTCEchelonGraph re-scored
  10. 2026-11-10 16:45 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  11. 2026-11-10 16:39 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  12. 2026-11-09 17:42 UTCEchelonGraph re-scored
  13. 2026-11-09 17:42 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  14. 2026-11-09 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  15. 2026-11-08 18:42 UTCEchelonGraph re-scored
  16. 2026-11-08 18:42 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  17. 2026-11-08 16:36 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  18. 2026-11-07 19:41 UTCEchelonGraph re-scored
  19. 2026-11-07 19:41 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  20. 2026-11-07 16:36 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  21. 2026-11-06 20:41 UTCEchelonGraph re-scored
  22. 2026-11-06 20:41 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  23. 2026-11-06 16:33 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  24. 2026-11-05 21:41 UTCEchelonGraph re-scored
  25. 2026-11-05 21:41 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
Show 75 more
  1. 2026-11-05 07:55 UTCOSV refresh
  2. 2026-11-04 22:36 UTCEchelonGraph re-scored
  3. 2026-11-04 22:36 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  4. 2026-11-04 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  5. 2026-11-03 23:35 UTCEchelonGraph re-scored
  6. 2026-11-03 23:35 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  7. 2026-11-03 16:44 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  8. 2026-11-03 00:35 UTCEchelonGraph re-scored
  9. 2026-11-03 00:35 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  10. 2026-11-02 16:42 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  11. 2026-11-02 01:34 UTCEchelonGraph re-scored
  12. 2026-11-02 01:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub severity MODERATE · GitHub CVSS 9.1
  13. 2026-11-01 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  14. 2026-11-01 02:34 UTCEchelonGraph re-scored
  15. 2026-11-01 02:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  16. 2026-10-31 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  17. 2026-10-31 03:34 UTCEchelonGraph re-scored
  18. 2026-10-31 03:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  19. 2026-10-30 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  20. 2026-10-30 04:34 UTCEchelonGraph re-scored
  21. 2026-10-30 04:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  22. 2026-10-29 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  23. 2026-10-29 05:34 UTCEchelonGraph re-scored
  24. 2026-10-29 05:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  25. 2026-10-28 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  26. 2026-10-28 06:34 UTCEchelonGraph re-scored
  27. 2026-10-28 06:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  28. 2026-10-27 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  29. 2026-10-27 07:34 UTCEchelonGraph re-scored
  30. 2026-10-27 07:33 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  31. 2026-10-26 16:29 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  32. 2026-10-26 05:51 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  33. 2026-10-25 16:47 UTCEchelonGraph re-scored
  34. 2026-10-25 16:31 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  35. 2026-10-25 06:50 UTCEchelonGraph re-scored
  36. 2026-10-25 06:49 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  37. 2026-10-24 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  38. 2026-10-24 07:49 UTCEchelonGraph re-scored
  39. 2026-10-24 07:49 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  40. 2026-10-23 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  41. 2026-10-23 08:46 UTCEchelonGraph re-scored
  42. 2026-10-23 08:46 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  43. 2026-10-22 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  44. 2026-10-22 09:45 UTCEchelonGraph re-scored
  45. 2026-10-22 09:45 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  46. 2026-10-21 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  47. 2026-10-21 10:42 UTCEchelonGraph re-scored
  48. 2026-10-21 10:41 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  49. 2026-10-20 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  50. 2026-10-20 11:41 UTCEchelonGraph re-scored
  51. 2026-10-20 11:41 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  52. 2026-10-19 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  53. 2026-10-19 13:26 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  54. 2026-10-18 19:24 UTCEchelonGraph re-scored
  55. 2026-10-18 19:24 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  56. 2026-10-18 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  57. 2026-10-18 05:50 UTCEchelonGraph re-scored
  58. 2026-10-17 20:22 UTCEchelonGraph re-scored
  59. 2026-10-17 20:22 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  60. 2026-10-17 16:32 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  61. 2026-10-16 21:19 UTCEchelonGraph re-scored
  62. 2026-10-16 21:18 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  63. 2026-10-16 16:37 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  64. 2026-10-15 18:15 UTCEchelonGraph re-scored
  65. 2026-10-15 18:14 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  66. 2026-10-15 16:30 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  67. 2026-10-14 16:31 UTCEPSS rescoreEPSS 0.4% · 29th percentile
  68. 2026-10-14 12:00 UTCEchelonGraph re-scored
  69. 2026-10-14 12:00 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  70. 2026-10-13 16:31 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  71. 2026-10-13 11:34 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  72. 2026-10-12 17:25 UTCEchelonGraph re-scored
  73. 2026-10-12 16:32 UTCEPSS rescoreEPSS 0.4% · 28th percentile
  74. 2026-10-12 12:25 UTCGHSA enrichmentGHSA-fvx8-q97q-cw73 · GitHub CVSS 9.1
  75. 2026-10-11 20:55 UTCEchelonGraph re-scored

Frequently asked(5)

What is CVE-2025-12642?
CVE-2025-12642 is a critical-severity vulnerability; its CVE record was published on November 3, 2025. lighttpd1.4.80 incorrectly merged trailer fields into headers after http request parsing. This behavior can be exploited to conduct HTTP Header Smuggling attacks. Successful exploitation may allow an attacker to: Bypass access control rules Inject unsafe input into backend logic that trusts request…
When was the CVE record for CVE-2025-12642 published?
The CVE record for CVE-2025-12642 was published on November 3, 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 October 19, 2026; the record at its source may have been updated since.
Is CVE-2025-12642 actively exploited?
CVE-2025-12642 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (31st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2025-12642?
CVE-2025-12642 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2025-12642?
An upstream fix for CVE-2025-12642 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.

Dependency Blast Radius

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