CVE-2026-54603: ruby-oauth oauth2
CVSS: 8.6v3.1HighAwaiting analysis
AliasesUBUNTU-CVE-2026-54603DEBIAN-CVE-2026-54603CGA-27gh-mwqp-53wmCGA-2vgg-mfg4-2pfgCGA-88pm-p756-jrpjCGA-fpxw-22rc-7g54CGA-gp57-37wq-9hr6CGA-j6w2-4wcp-x8hcCGA-vpww-58wg-6vrwCGA-wrxp-5hwc-277qCGA-25rc-ghcq-q485CGA-2689-jvg3-6cc2CGA-2c55-879p-m2crCGA-2f7g-pw4h-m97cCGA-2qcf-86cv-j5pjCGA-4hqq-q66m-w5j9CGA-57v5-wpmj-pg44CGA-59c9-phjf-3qq4CGA-5qf7-m9vf-pm37CGA-5qpj-8vhx-5h73CGA-7x2x-pxrf-rp3qCGA-86j2-m9j6-hc2rCGA-8f28-j85r-x5jxCGA-9827-86x2-ppjfCGA-9q2p-jvcc-r4j7CGA-f4p8-q3xc-86wcCGA-fgh5-8ggr-5pm3CGA-gchv-jj9m-xp2rCGA-gfqc-w422-97f8CGA-ggr8-9jr2-9hxxCGA-ghv7-vqwv-w3q9CGA-gmrv-5f22-5hpmCGA-gmv4-vmv6-j438CGA-h8wj-6cw3-66qvCGA-hq47-chw4-2hf6CGA-j656-8qq2-w7cpCGA-mccr-mvr3-jmvfCGA-mj67-pggq-pw6hCGA-mm77-qp5x-x7grCGA-p9j8-fgw3-rggqCGA-pgrh-cq3r-x6gjGHSA-pp92-crg2-gfv9CGA-qg2v-9rr2-prqgCGA-rgv6-r6cp-95q5CGA-vp23-4wp4-qcphCGA-w854-86h6-4hm4CGA-x38v-wqqm-4x2hCGA-xf6q-p78x-vc62CGA-xff3-vxpq-h36vCGA-xh5m-9gp7-vhm6CGA-xw2c-wx45-c956
Published 28-07-2026Last modified 05-10-2026
Vulnerability summary
CVE-2026-54603 is a high (CVSS 8.6) vulnerability in ruby-oauth oauth2. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 37.6% of scored vulnerabilities.
CVSS score
8.6/10
010
High · v3.1 (CVE.org)EPSS score
0.45%
0%100%
Low · +0.01 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 28-07-2026PublishedVulnerability first disclosed.
- 05-10-2026Last modifiedVulnerability information updated.
Description
OAuth2 is a Ruby wrapper for the OAuth 2.0 and 2.1 authorization frameworks, including OpenID Connect (OIDC). From 0.4.0 to 2.0.21, a protocol-relative redirect Location returned to OAuth2::Client#request overrides the request authority, so the bearer Authorization header is sent to an attacker-controlled host, leaking the credential. This issue is fixed in version 2.0.22.
CVSS metrics
7 scores · 7 sources · 1 versionHigh 8.6Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:NSourcesAll 7 agree
- OSV · UbuntuEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- OSV · WolfiEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- OSV · RubygemsEcosystem advisory · calculated8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- NVDNIST8.6HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
EPSS trend
Probability
0.45%
Chance of exploitation in the next 30 days
Percentile
38%
Versus all other CVEs
30-day change
+0.01 pp
From 0.43% on 20-09-2026
20-09-202620-10-2026
EPSS score0.45%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
- CWE-601URL Redirection to Untrusted Site ('Open Redirect')The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect.
Affected systems
Chainguard24 products
- commercial-gitlab-rails-ee-19.1All versions (No fix recorded)
- commercial-gitlab-rails-ee-fips-19.1All versions (No fix recorded)
- gitlab-rails-ce-18.1All versions (No fix recorded)
- gitlab-rails-ce-18.10All versions (No fix recorded)
- gitlab-rails-ce-18.11All versions (No fix recorded)
Wolfi4 products
- ruby3.2-oauth2< 2.0.22-r0
- ruby3.3-oauth2< 2.0.22-r0
- ruby3.4-oauth2< 2.0.22-r0
- ruby4.0-oauth2< 2.0.22-r1
Debian1 product
- ruby-oauth2< 1.4.4-1+deb12u1 | All versions (No fix recorded) | < 2.0.25-1
Ruby-oauth1 product
- oauth2≥ 0.4.0, < 2.0.22
RubyGems1 product
- oauth2≥ 0.4.0, < 2.0.22
Ubuntu1 product
- ruby-oauth2All versions (No fix recorded)
6 vendors · 32 products
References
11 links
Show all 11 references
- github.com/ruby-oauth/oauth2PACKAGE