CVE-2026-67353: guzzle
Vulnerability summary
CVE-2026-67353 is a medium (CVSS 6.9) vulnerability in guzzle. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 01-08-2026PublishedVulnerability first disclosed.
- 08-10-2026Last modifiedVulnerability information updated.
Description
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 metrics
9 scores · 6 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · DebianEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · WolfiEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- NVDNIST6.9MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.42%
Chance of exploitation in the next 30 days
Percentile
35%
Versus all other CVEs
30-day change
+0.17 pp
From 0.25% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard6 products
- drupal-11.3< 11.3.16-r0
- nextcloud-server-31< 31.0.14-r5
- nextcloud-server-32< 32.0.12-r6
- nextcloud-server-33< 33.0.6-r8
- nextcloud-server-34< 34.0.1-r9
Wolfi2 products
- nextcloud-server-32< 32.0.12-r6
- nextcloud-server-33< 33.0.6-r8
Debian1 product
- guzzleAll versions (No fix recorded) | < 7.15.1-1
Guzzle1 product
- guzzle< 7.15.1
Ubuntu1 product
- guzzleAll versions (No fix recorded)
5 vendors · 11 products
References
7 links- www.vulncheck.com/advisories/guzzlehttp-guzzle-before-unbounded-cookie-denial-of-serviceThird Party AdvisoryREPORTAdvisory
