CVE-2026-54277

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the max_line_size check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send oversized lines through the HTTP parser and use an excessive amount of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
24.1%
KEV
Not listed

Published

June 15, 2026

Last Modified

June 30, 2026

Advisory Details (2)

Auto-updated Jun 22, 2026
Patch available. Sources: github_commit, github.
github Patch Available

C HTTP Parser Bypasses max_line_size for Fragmented Lines · Advisory · aio-libs/aiohttp · GitHub

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-63hw-fmq6-xxg2
github_commit

commit 5ab61bb4cd88 (aio-libs/aiohttp)

Fix landed in aio-libs/aiohttp commit 5ab61bb4cd88 — awaiting tagged release

https://github.com/aio-libs/aiohttp/commit/5ab61bb4cd88f19b712f12c7c9295fe262bf804d

Vendor Advisories for CVE-2026-54277(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)
PyPI(1)
PackageVulnerable rangeFixed inDependents
aiohttp0.1 ... 3.9.5 (307 versions)3.14.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 22× in last 7d / 42× 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. 2026-07-07 00:18 UTCEG score recompute
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 02:23 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 01:47 UTCEG score recompute
  7. 2026-07-05 12:34 UTCEG score recompute
  8. 2026-07-05 02:31 UTCEPSS rescore
  9. 2026-07-05 02:30 UTCEPSS rescore
  10. 2026-07-04 23:12 UTCEG score recompute
  11. 2026-07-04 10:00 UTCEG score recompute
  12. 2026-07-04 06:31 UTCEPSS rescore
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-03 14:16 UTCEG score recompute
  15. 2026-07-03 00:39 UTCEG score recompute
  16. 2026-07-02 11:18 UTCEG score recompute
  17. 2026-07-01 21:22 UTCEG score recompute
  18. 2026-07-01 15:07 UTCEPSS rescore
  19. 2026-07-01 08:10 UTCEG score recompute
  20. 2026-06-30 23:22 UTCEPSS rescore
  21. 2026-06-30 18:57 UTCEG score recompute▲ 0.90
  22. 2026-06-30 18:32 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  23. 2026-06-29 19:12 UTCEG score recompute
  24. 2026-06-29 14:06 UTCEPSS rescore
  25. 2026-06-29 14:06 UTCEPSS rescore
Show 17 more
  1. 2026-06-28 19:27 UTCEG score recompute
  2. 2026-06-28 14:07 UTCEPSS rescore
  3. 2026-06-28 04:56 UTCEPSS rescore
  4. 2026-06-28 04:56 UTCEPSS rescore
  5. 2026-06-27 19:42 UTCEG score recompute
  6. 2026-06-27 03:08 UTCEPSS rescore
  7. 2026-06-26 19:55 UTCEG score recompute
  8. 2026-06-25 20:11 UTCEG score recompute
  9. 2026-06-25 13:49 UTCEPSS rescore
  10. 2026-06-24 20:25 UTCEG score recompute
  11. 2026-06-24 14:05 UTCEPSS rescore
  12. 2026-06-23 21:33 UTCEPSS rescore
  13. 2026-06-23 21:33 UTCEPSS rescore
  14. 2026-06-23 19:29 UTCEG score recompute
  15. 2026-06-22 19:42 UTCEG score recompute▲ 6.60
  16. 2026-06-22 19:40 UTCNVD updateCVSS v3 → 6.6 · CVSS v4 → 6.6
  17. 2026-06-15 20:47 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-54277?
CVE-2026-54277 is a high vulnerability published on June 15, 2026. AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, it is possible to bypass the maxlinesize check in parts of an HTTP request in the C parser. If using the optimised C parser (the default in pre-built wheels), then an attacker may be able to send…
When was CVE-2026-54277 disclosed?
CVE-2026-54277 was first published in the National Vulnerability Database on June 15, 2026, with the most recent update on June 30, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-54277 actively exploited?
CVE-2026-54277 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.1% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-54277?
CVE-2026-54277 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-54277?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-54277, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-54277

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