CVE-2026-67353

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH confidence

Score 5.3 from GitHub Security Advisory published 2026-08-01. a secondary CVSS source baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

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

guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the CookieJar that accepts unlimited Set-Cookie header fields with no size restrictions. Attackers can return many large cookies from a malicious server, causing Guzzle to store excessive data in memory and generate oversized Cookie headers that fail in handlers or destination servers.

CVSS v3
5.3
EG Score
5.3(high)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
16%
KEV
Not listed

Published

August 1, 2026

Last Modified

August 3, 2026

Advisory Details (2)

Auto-updated Aug 1, 2026
Patch available. Sources: github.
generic

guzzlehttp/guzzle before 7.15.1 Unbounded Cookie Denial of Service | Advisories | VulnCheck

https://www.vulncheck.com/advisories/guzzlehttp-guzzle-before-unbounded-cookie-denial-of-service
github Patch Available

Unbounded response cookies risk denial of service in guzzlehttp/guzzle · Advisory · guzzle/guzzle · GitHub

https://github.com/guzzle/guzzle/security/advisories/GHSA-f283-ghqc-fg79

Vendor Advisories for CVE-2026-67353(1)

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

Affected Packages

(4 across 4 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
guzzle7.11.0-1 ... 8.0.1-1 (13 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
guzzle7.11.0-1 ... 8.0.1-1 (12 versions)——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
guzzle7.11.0-1 ... 7.9.2-0.1 (10 versions)7.15.1-1—
Packagist(1)
PackageVulnerable rangeFixed inDependents
guzzlehttp/guzzle4.0.0 ... v3.8.1 (174 versions)7.15.1—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 51× 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. 2026-08-25 17:30 UTCEG score recompute
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-24 19:20 UTCEG score recompute
  4. 2026-08-23 21:24 UTCEG score recompute
  5. 2026-08-23 00:19 UTCEPSS rescore
  6. 2026-08-22 01:34 UTCEG score recompute
  7. 2026-08-21 23:49 UTCEPSS rescore
  8. 2026-08-21 03:39 UTCEG score recompute
  9. 2026-08-20 22:56 UTCEPSS rescore
  10. 2026-08-20 05:45 UTCEG score recompute
  11. 2026-08-19 17:04 UTCEPSS rescore
  12. 2026-08-19 07:50 UTCEG score recompute
  13. 2026-08-18 13:48 UTCEPSS rescore
  14. 2026-08-18 09:53 UTCEG score recompute
  15. 2026-08-17 13:47 UTCEPSS rescore
  16. 2026-08-17 11:56 UTCEG score recompute
  17. 2026-08-16 14:56 UTCEPSS rescore
  18. 2026-08-16 14:02 UTCEG score recompute
  19. 2026-08-15 16:08 UTCEG score recompute
  20. 2026-08-15 01:30 UTCEPSS rescore
  21. 2026-08-14 18:13 UTCEG score recompute
  22. 2026-08-13 22:00 UTCEPSS rescore
  23. 2026-08-12 22:24 UTCEG score recompute
  24. 2026-08-12 13:51 UTCEPSS rescore
  25. 2026-08-12 00:29 UTCEG score recompute
Show 26 more
  1. 2026-08-11 02:35 UTCEG score recompute
  2. 2026-08-11 00:00 UTCEPSS rescore
  3. 2026-08-10 04:40 UTCEG score recompute
  4. 2026-08-09 13:47 UTCEPSS rescore
  5. 2026-08-09 06:46 UTCEG score recompute
  6. 2026-08-08 16:37 UTCEPSS rescore
  7. 2026-08-08 08:52 UTCEG score recompute
  8. 2026-08-07 10:57 UTCEG score recompute
  9. 2026-08-06 13:47 UTCEPSS rescore
  10. 2026-08-06 13:02 UTCEG score recompute
  11. 2026-08-05 19:17 UTCEPSS rescore
  12. 2026-08-05 19:17 UTCEPSS rescore
  13. 2026-08-04 17:13 UTCEG score recompute
  14. 2026-08-04 15:10 UTCEPSS rescore
  15. 2026-08-04 10:39 UTCEPSS rescore
  16. 2026-08-03 19:19 UTCEG score recompute
  17. 2026-08-03 19:19 UTCGHSA enrichment
  18. 2026-08-03 18:23 UTCEG score recompute
  19. 2026-08-03 18:23 UTCGHSA enrichment
  20. 2026-08-03 10:36 UTCEPSS rescore
  21. 2026-08-03 09:09 UTCGHSA enrichment
  22. 2026-08-02 11:14 UTCEG score recompute
  23. 2026-08-02 11:14 UTCGHSA enrichment
  24. 2026-08-01 13:19 UTCEG score recompute
  25. 2026-08-01 12:44 UTCEG score recompute
  26. 2026-08-01 12:42 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-67353?
CVE-2026-67353 is a medium vulnerability published on August 1, 2026. guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the CookieJar that accepts unlimited Set-Cookie header fields with no size restrictions. Attackers can return many large cookies from a malicious server, causing Guzzle to store excessive data in memory and…
When was CVE-2026-67353 disclosed?
CVE-2026-67353 was first published in the National Vulnerability Database on August 1, 2026, with the most recent update on August 3, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67353 actively exploited?
CVE-2026-67353 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 84.3% of all scored CVEs.
What is the CVSS score of CVE-2026-67353?
CVE-2026-67353 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-67353?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67353, 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-2026-67353

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