CVE-2026-78660

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 CISA-ADP (Vulnrichment) CVSS v3.1 (NVD's own analysis pending). EPSS exploit probability: 0.5% (46th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from CISA-ADP (Vulnrichment) CVSS v3.1
Sources: CISA-ADP (Vulnrichment) CVSS v3.1, EPSS

Also known asEUVD-2026-95425 (ENISA EUVD) · GO-2026-6610 (OSV.dev)Source: ENISA EUVD

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: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a reverse proxy. If the HTTP/1 client also does not behave strictly enough, this can result in response smuggling.

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 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)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.5% × 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
0.5%
EPSS %ILE
46th
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 (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.CISA-ADP (Vulnrichment) CVSS v3.1 · CVSS v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-09). 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.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).

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.

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

October 8, 2026

Last Modified

October 9, 2026

Advisory Details (5)

Auto-updated Oct 9, 2026
Patch available.
Web page

GO-2026-6610 - Go Packages

https://pkg.go.dev/vuln/GO-2026-6610
Web page

net/http/internal/http2: transport accepts multiple Content-Length headers · Issue #81115 · golang/go · GitHub

https://go.dev/issue/81115

Patch Availability(11)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
ubuntugolang-1.22-src (1.22.2-2~20.04.3) @ focal2026-11-03ubuntu
redhatgo-toolset:rhel8-8040020261027035356.522a0ee42026-10-27redhat
redhatgolang-0:1.26.10-1.el9_62026-10-21redhat
redhatgo-toolset:rhel8-8080020261020152326.6b4b45d82026-10-21redhat
redhatgolang-0:1.26.10-1.el9_42026-10-21redhat
redhatgo-toolset:rhel8-8060020261020153812.97d7f71f2026-10-21redhat
redhatgolang-0:1.26.10-1.el10_02026-10-21redhat
redhatgolang-0:1.26.10-1.el9_22026-10-21redhat
redhatgolang-0:1.26.10-1.el10_22026-10-20redhat
redhatgolang-0:1.26.10-1.el9_82026-10-20redhat
redhatgo-toolset:rhel8-8100020261020054335.a3795dee2026-10-20redhat

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

(11 across 5 ecosystems)
Debian:14(4)
PackageVulnerable rangeFix by version rangeDependents
golang-1.251.25.0-1 ... 1.25.9-1 (20 versions)
  • every version on: no fix on record
—
golang-1.261.26.0-1 ... 1.26~rc3-2 (23 versions)
  • every version up to 1.26.9-1: fixed in 1.26.9-1
—
golang-1.271.27.0-1 ... 1.27~rc3-1 (9 versions)
  • every version up to 1.27.2-1: fixed in 1.27.2-1
—
golang-golang-x-net1:0.27.0-2 ... 1:0.58.0-1 (10 versions)
  • every version up to 1:0.60.0-1: fixed in 1:0.60.0-1
—
Debian:12(2)
PackageVulnerable rangeFix by version rangeDependents
golang-1.191.19.10-1 ... 1.19.9-1 (12 versions)
  • every version on: no fix on record
—
golang-golang-x-net1:0.10.0-1 ... 1:0.7.0+dfsg-1 (28 versions)
  • every version on: no fix on record
—
Debian:13(2)
PackageVulnerable rangeFix by version rangeDependents
golang-1.241.24.12-1 ... 1.24.9-1 (10 versions)
  • every version on: no fix on record
—
golang-golang-x-net1:0.27.0-2 ... 1:0.60.0-1 (11 versions)
  • every version on: no fix on record
—
Go(2)
PackageVulnerable rangeFix by version rangeDependents
golang.org/x/net—
  • every version up to 0.60.0: fixed in 0.60.0
—
stdlib—
  • every version up to 1.26.9: fixed in 1.26.9
  • 1.27.0-0 up to 1.27.2: fixed in 1.27.2
—
Alpine:v3.24(1)
PackageVulnerable rangeFix by version rangeDependents
go—
  • every version up to 1.26.9-r0: fixed in 1.26.9-r0
—

Weakness Classification(1)

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

Additional Vendor Advisories

(1)

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 8× in last 7d / 33× 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.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.5% · 46th percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  4. 2026-11-09 20:30 UTCEchelonGraph re-scored
  5. 2026-11-09 20:30 UTCVendor advisory
  6. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  7. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  8. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.5% · 45th percentile
  9. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  10. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  11. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  12. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  13. 2026-11-03 07:44 UTCEchelonGraph re-scored
  14. 2026-11-03 07:44 UTCVendor advisory
  15. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  16. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  17. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  18. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  19. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  20. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  21. 2026-10-27 18:48 UTCEchelonGraph re-scored
  22. 2026-10-27 18:48 UTCVendor advisory
  23. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  25. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
Show 36 more
  1. 2026-10-25 14:00 UTCEchelonGraph re-scored
  2. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  3. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  4. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  5. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  6. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  7. 2026-10-20 08:03 UTCEchelonGraph re-scored
  8. 2026-10-20 08:03 UTCVendor advisory
  9. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  10. 2026-10-18 03:11 UTCEchelonGraph re-scored
  11. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  12. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  13. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  14. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  15. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  16. 2026-10-13 06:46 UTCEchelonGraph re-scored
  17. 2026-10-13 06:46 UTCVendor advisory
  18. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  19. 2026-10-12 15:36 UTCEchelonGraph re-scored
  20. 2026-10-11 19:22 UTCEchelonGraph re-scored
  21. 2026-10-11 16:38 UTCEchelonGraph re-scored
  22. 2026-10-11 13:57 UTCEchelonGraph re-scored
  23. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  24. 2026-10-11 07:51 UTCEchelonGraph re-scored
  25. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 21st percentile
  26. 2026-10-10 06:19 UTCEchelonGraph re-scored
  27. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.2% · 7th percentile
  28. 2026-10-09 17:34 UTCEchelonGraph re-scoredAssessed again: 7.5 HIGH
  29. 2026-10-09 17:33 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  30. 2026-10-09 16:58 UTCEchelonGraph re-scored▼ 7.50
  31. 2026-10-09 16:52 UTCNVD update
  32. 2026-10-09 16:28 UTCEchelonGraph re-scoredFirst assessed: 7.5 HIGH
  33. 2026-10-09 16:28 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  34. 2026-10-08 23:20 UTCNVD update
  35. 2026-10-08 22:58 UTCEchelonGraph re-scored
  36. 2026-10-08 22:58 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-78660?
CVE-2026-78660 is a high-severity vulnerability; its CVE record was published on October 8, 2026. Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a…
When was the CVE record for CVE-2026-78660 published?
The CVE record for CVE-2026-78660 was published on October 8, 2026. 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 9, 2026; the record at its source may have been updated since.
Is CVE-2026-78660 actively exploited?
CVE-2026-78660 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (46th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-78660?
CVE-2026-78660 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-78660?
A fix for CVE-2026-78660 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-78660 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-78660

Explore →

Is Your Infrastructure Affected by CVE-2026-78660?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.