CVE-2026-63075

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-08-25. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — Patch released this week
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0

A fix is available — apply it.

Issue summary: When OpenSSL processes QUIC traffic from a peer that repeatedly sends ack-eliciting packets while not acknowledging ACK-only responses, the QUIC stack can retain ACK-only packet metadata for the lifetime of the connection.

Impact summary: A remote peer that can complete a QUIC handshake can cause connection-scoped memory growth which may lead to Denial of Service through memory exhaustion, especially with sustained traffic or many concurrent QUIC connections.

CWE: CWE-770: Allocation of Resources Without Limits or Throttling

Description: When the OpenSSL QUIC stack sends an ACK-only packet, there is no requirement by the QUIC protocol that the peer will acknowledge that ACK-only packet (i.e. it is itself not ack-eliciting). However, the OpenSSL implementation stores the metadata about the ACK frames regardless. In and of itself that's ok, but if a malicious peer establishes a connection, and then drives the connection such that ACK-only packets are forced from the OpenSSL implementation peer (i.e., by sending numerous PING frames), and then withholding any subsequent acks for ack-eliciting data, like legitimate data, said malicious peer can force inappropriate memory growth on the OpenSSL peer, potentially leading to a Denial of Service.

The fix is to ensure that we account for the transmission of the ACK-only packet in the packet histories high and low watermark without actually storing the ACK-only packet metadata itself.

FIPS impact: no The OpenSSL FIPS module is not affected as the QUIC code is outside the FIPS module boundary.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

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
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

August 25, 2026

Last Modified

August 28, 2026

Advisory Details (5)

Auto-updated Aug 25, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
github_commit

commit c902e5f16d6a (openssl/openssl)

Fix landed in openssl/openssl commit c902e5f16d6a — awaiting tagged release

https://github.com/openssl/openssl/commit/c902e5f16d6a9e130e96d3ca6d8f64d71652e393
github_commit

commit 7c98d7973854 (openssl/openssl)

Fix landed in openssl/openssl commit 7c98d7973854 — awaiting tagged release

https://github.com/openssl/openssl/commit/7c98d79738549df92868e7dd9be4bbf061eed709
github_commit

commit bf84721c2548 (openssl/openssl)

Fix landed in openssl/openssl commit bf84721c2548 — awaiting tagged release

https://github.com/openssl/openssl/commit/bf84721c2548351176e367e6de505792f0118dc6
github_commit

commit 7308946576b1 (openssl/openssl)

Fix landed in openssl/openssl commit 7308946576b1 — awaiting tagged release

https://github.com/openssl/openssl/commit/7308946576b12e64b8be53bcf0a120354b2b42bc
generic
https://openssl-library.org/news/secadv/20260825.txt

Vendor Advisories for CVE-2026-63075(3)

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

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuopenssl-provider-legacy (3.5.5-1ubuntu3.4) @ resolute2026-08-30ubuntu
redhatopenssl3-main-3.5.8-0.1.hum12026-08-25redhat
redhatopenssl-main-3.5.8-0.1.hum12026-08-25redhat

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.

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 33× in last 7d / 33× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-08-30 04:46 UTCEG score recompute
  2. 2026-08-30 04:46 UTCVendor advisory
  3. 2026-08-30 04:46 UTCGHSA enrichment
  4. 2026-08-30 01:22 UTCEPSS rescore
  5. 2026-08-29 17:51 UTCVendor advisory
  6. 2026-08-29 17:51 UTCGHSA enrichment
  7. 2026-08-29 06:54 UTCEG score recompute
  8. 2026-08-29 06:54 UTCVendor advisory
  9. 2026-08-29 06:54 UTCGHSA enrichment
  10. 2026-08-28 21:42 UTCEPSS rescore
  11. 2026-08-28 19:59 UTCVendor advisory
  12. 2026-08-28 19:59 UTCGHSA enrichment
  13. 2026-08-28 09:00 UTCVendor advisory
  14. 2026-08-28 08:59 UTCGHSA enrichment
  15. 2026-08-27 22:01 UTCEG score recompute
  16. 2026-08-27 22:01 UTCVendor advisory
  17. 2026-08-27 22:01 UTCGHSA enrichment
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-27 11:06 UTCVendor advisory
  20. 2026-08-27 11:05 UTCGHSA enrichment
  21. 2026-08-27 00:09 UTCEG score recompute
  22. 2026-08-27 00:09 UTCVendor advisory
  23. 2026-08-27 00:09 UTCGHSA enrichment
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-26 13:13 UTCGHSA enrichment
Show 8 more
  1. 2026-08-26 02:16 UTCEG score recompute
  2. 2026-08-26 02:16 UTCVendor advisory
  3. 2026-08-26 02:16 UTCGHSA enrichment
  4. 2026-08-25 14:56 UTCEG score recompute▲ 7.50
  5. 2026-08-25 14:54 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  6. 2026-08-25 13:21 UTCNVD update
  7. 2026-08-25 13:16 UTCEG score recompute
  8. 2026-08-25 13:15 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-63075?
CVE-2026-63075 is a high vulnerability published on August 25, 2026. Issue summary: When OpenSSL processes QUIC traffic from a peer that repeatedly sends ack-eliciting packets while not acknowledging ACK-only responses, the QUIC stack can retain ACK-only packet metadata for the lifetime of the connection. Impact summary: A remote peer that can complete a QUIC…
When was CVE-2026-63075 disclosed?
CVE-2026-63075 was first published in the National Vulnerability Database on August 25, 2026, with the most recent update on August 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63075 actively exploited?
CVE-2026-63075 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 60.6% of all scored CVEs.
What is the CVSS score of CVE-2026-63075?
CVE-2026-63075 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-63075?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63075, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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