CVE-2026-57497

MEDIUMPre-NVD 5.35.3
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (42nd 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
5.3EG
EchelonGraph verdictMonitorRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 5.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

webtransport-go is an implementation of the WebTransport protocol. Prior to 0.11.1, Session.parseNextCapsule() in session.go skips an unknown WebTransport capsule on the HTTP/3 request stream by calling io.ReadAll on the capsule reader, retaining the complete declared capsule body in memory. A malicious peer can send a large unknown capsule and cause a client or server to allocate memory for the full payload; QUIC flow control does not bound the total retained allocation because reading advances the flow-control window while the received bytes remain in memory. The resulting memory and resource exhaustion can disrupt or crash the affected process. This issue is fixed in version 0.11.1.

CVSS v3
5.3
EG Score
5.3MEDIUMmedium confidence
EG Risk
39
EG Risk 39/100

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)
Severity53% × 45%
The EG Score, 5.3 of 10.
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
42nd
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

July 24, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Sep 14, 2026
Patch available. Sources: github_commit, github_release, github, github_pr.
GitHub release Patch Available

v0.11.1

Patch available: quic-go/webtransport-go v0.11.1

https://github.com/quic-go/webtransport-go/releases/tag/v0.11.1
GitHub commit Patch Available

commit 3aecd1173657 (quic-go/webtransport-go)

Patch available: quic-go/webtransport-go v0.11.1 (contains commit 3aecd1173657)

https://github.com/quic-go/webtransport-go/commit/3aecd11736579530ff067651c30a543eb0b4b8c4
GitHub pull request Patch Available

avoid buffering skipped capsules

Patch available: quic-go/webtransport-go v0.12.0 (PR #290 merged 2026-06-20)

https://github.com/quic-go/webtransport-go/pull/290
GitHub advisoryMentions a patch (unverified)

Memory Exhaustion Attack due to Buffering of Unknown Capsules · Advisory · quic-go/webtransport-go · GitHub

https://github.com/quic-go/webtransport-go/security/advisories/GHSA-g35j-m5xg-vh3q

Vendor Advisories for CVE-2026-57497(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/quic-go/webtransport-go—
  • every version up to 0.11.1: fixed in 0.11.1
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 43× 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.

  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  3. 2026-10-12 15:54 UTCEG score recompute
  4. 2026-10-11 19:37 UTCEG score recompute
  5. 2026-10-11 16:52 UTCEG score recompute
  6. 2026-10-11 14:15 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  10. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  15. 2026-10-04 07:42 UTCEG score recompute
  16. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  17. 2026-10-02 19:44 UTCEG score recompute
  18. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  19. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  20. 2026-09-30 18:11 UTCEG score recompute
  21. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  22. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  23. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  24. 2026-09-28 04:26 UTCEG score recompute
  25. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
Show 21 more
  1. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  2. 2026-09-25 10:01 UTCEG score recompute
  3. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  4. 2026-09-24 00:55 UTCEG score recompute
  5. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  6. 2026-09-22 22:09 UTCEG score recompute
  7. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  8. 2026-09-20 01:39 UTCEG score recompute
  9. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  10. 2026-09-18 10:48 UTCEG score recompute
  11. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  12. 2026-09-17 09:13 UTCEG score recompute
  13. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  14. 2026-09-16 06:39 UTCEG score recompute
  15. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.5% · 39th percentile
  16. 2026-09-14 20:27 UTCEG score recompute
  17. 2026-09-14 20:16 UTCEG score recompute
  18. 2026-09-14 18:08 UTCEG score recompute
  19. 2026-07-30 16:03 UTCEG score recompute
  20. 2026-07-27 11:17 UTCEG score recompute
  21. 2026-07-24 21:12 UTCEG score recomputeFirst assessed: 5.3 MEDIUM

Related CVEs(same product + same CWE)

Same product

3 shown

Go:github.com/quic-go/webtransport-go

Frequently asked(5)

What is CVE-2026-57497?
CVE-2026-57497 is a medium-severity vulnerability; its CVE record was published on July 24, 2026. webtransport-go is an implementation of the WebTransport protocol. Prior to 0.11.1, Session.parseNextCapsule() in session.go skips an unknown WebTransport capsule on the HTTP/3 request stream by calling io.ReadAll on the capsule reader, retaining the complete declared capsule body in memory. A…
When was the CVE record for CVE-2026-57497 published?
The CVE record for CVE-2026-57497 was published on July 24, 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 September 30, 2026; the record at its source may have been updated since.
Is CVE-2026-57497 actively exploited?
CVE-2026-57497 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (42nd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-57497?
CVE-2026-57497 has a CVSS base score of 5.3 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-57497?
A fix for CVE-2026-57497 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-57497 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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