CVE-2026-54873

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-29. 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: 0.5%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Issue summary: QUIC process may keep memory for QUIC packet buffer for much longer period than necessary.

Impact summary: Remote peer can exploit this vulnerability by sending maliciously crafted packets, making the local QUIC stack to keep the memory for packet buffers allocated. The time for which the memory remains allocated is entirely under the control of the potentially malicious remote peer.

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

Description: To save copy operation from the packet buffer to the stream reassemble buffer the QUIC stack leaves the stream data on the packet buffer waiting to be copied to a buffer provided by the local receiving application. The QUIC stack releases a reference to the packet buffer only after the data are copied to the application buffer. This design is more efficient for legitimate data transfers but enables an attacker to allocate a lot more memory than actually required by the data kept in the receiving stream buffer.

To mitigate the vulnerability, the QUIC stack now calculates and monitors memory overhead for every stream. The memory overhead for a single stream frame is calculated as a difference between the size of the whole packet that carries the stream frame and the size of the stream frame itself. The memory overhead for a single stream frame is added to the total (cumulative) memory overhead QUIC stack keeps for each stream. Once the cumulative memory overhead exceeds 64kB, the QUIC stack moves the stream frame data from the packet buffer to the stream buffer, starting with the next packet received.

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

CVSS v3
7.5
EG Score
7.5HIGHhigh confidence
EG Risk
49
EG Risk 49/100CISA SSVC

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%
CISA SSVC: Track at low or medium mission impact; Attend at high (mission-essential systems).
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
37th
KEV
Not listed

CISA SSVCTrack 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). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 29, 2026

Last Modified

September 30, 2026

Advisory Details (5)

Auto-updated Sep 30, 2026
Patch available. Sources: github_commit.
github_commit

commit 3ea6213e050e (openssl/openssl)

Fix landed in openssl/openssl commit 3ea6213e050e — awaiting tagged release

https://github.com/openssl/openssl/commit/3ea6213e050e938ecbbf8c4eff32bec2736780eb
github_commit

commit 279e7ee1392a (openssl/openssl)

Fix landed in openssl/openssl commit 279e7ee1392a — awaiting tagged release

https://github.com/openssl/openssl/commit/279e7ee1392af98785746788168749491c74bd53
github_commit

commit 7127fb10888b (openssl/openssl)

Fix landed in openssl/openssl commit 7127fb10888b — awaiting tagged release

https://github.com/openssl/openssl/commit/7127fb10888b49711c63128a09e524c0d2d5d0b2
github_commit

commit 1f643b8bc735 (openssl/openssl)

Fix landed in openssl/openssl commit 1f643b8bc735 — awaiting tagged release

https://github.com/openssl/openssl/commit/1f643b8bc735487b500a1f68a7fb3a22d5e38e23

Patch Availability(3)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuopenssl-provider-legacy (3.5.5-1ubuntu3.7) @ resolute2026-10-04ubuntu
redhatopenssl3-main-3.5.9-0.1.hum12026-09-30redhat
redhatopenssl-main-3.5.9-0.1.hum12026-09-30redhat

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 28× in last 7d / 28× 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. 2026-10-04 11:17 UTCVendor advisory
  2. 2026-10-04 11:17 UTCGHSA enrichment
  3. 2026-10-03 23:02 UTCEG score recompute
  4. 2026-10-03 23:02 UTCVendor advisory
  5. 2026-10-03 23:02 UTCGHSA enrichment
  6. 2026-10-03 14:26 UTCEPSS rescore
  7. 2026-10-03 10:47 UTCVendor advisory
  8. 2026-10-03 10:47 UTCGHSA enrichment
  9. 2026-10-02 22:32 UTCEG score recompute
  10. 2026-10-02 22:32 UTCVendor advisory
  11. 2026-10-02 22:32 UTCGHSA enrichment
  12. 2026-10-02 17:56 UTCEPSS rescore
  13. 2026-10-02 10:17 UTCVendor advisory
  14. 2026-10-02 10:17 UTCGHSA enrichment
  15. 2026-10-01 22:03 UTCEG score recompute
  16. 2026-10-01 22:02 UTCGHSA enrichment
  17. 2026-10-01 19:50 UTCEPSS rescore
  18. 2026-10-01 09:44 UTCEG score recompute
  19. 2026-10-01 09:44 UTCGHSA enrichment
  20. 2026-09-30 21:29 UTCGHSA enrichment
  21. 2026-09-30 20:26 UTCEG score recompute▲ 7.50
  22. 2026-09-30 20:26 UTCGHSA enrichment
  23. 2026-09-30 20:25 UTCMITRE cvelistV5CVSS v3 → 7.5 · severity → HIGH
  24. 2026-09-30 15:03 UTCEPSS rescore
  25. 2026-09-29 22:00 UTCGHSA enrichment
Show 3 more
  1. 2026-09-29 16:24 UTCNVD update
  2. 2026-09-29 15:38 UTCEG score recompute
  3. 2026-09-29 15:38 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-54873?
CVE-2026-54873 is a high vulnerability published on September 29, 2026. Issue summary: QUIC process may keep memory for QUIC packet buffer for much longer period than necessary. Impact summary: Remote peer can exploit this vulnerability by sending maliciously crafted packets, making the local QUIC stack to keep the memory for packet buffers allocated. The time for…
When was CVE-2026-54873 disclosed?
CVE-2026-54873 was first published on September 29, 2026, with the most recent update on September 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54873 actively exploited?
CVE-2026-54873 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54873?
CVE-2026-54873 has a CVSS v3.1 base score of 7.5 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-54873?
A fix for CVE-2026-54873 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-54873 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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