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Full vulnerability report · 2026
CVE-2026-27812High confidence

Sub2API Vulnerable to Password Reset Poisoning via Host Header Trust Issue, Leading to Account Takeover

Wei-Shaw · sub2api

Official source article: GitHub GHSA-VC2Q-289V-74G3 ↗. Check the applicable product and release in the original source.

8.0HighCVSS 4.0
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityHighOperational priority:High, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 0.44% for the current model date.

Compensating controls

  • Apply the linked authoritative mitigation while planning the permanent fix.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Wei-Shaw sub2api and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 30 daysRemediation target: Within 180 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-8782

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Mitigation available
01

What, why and how

Sub2API is an AI API gateway platform designed to distribute and manage API quotas from AI product subscriptions. A vulnerability in versions prior to 0.1.85 is a Password Reset Poisoning (Host Header / Forwarded Header trust issue), which allows attackers to manipulate the password reset link. Attackers can exploit this flaw to inject their own domain into the password reset link, leading to the potential for account takeover. The vulnerability has been fixed in version v0.1.85. If upgrading is not immediately possible, users can mitigate the vulnerability by disabling the "forgot password" feature until an upgrade to a patched version can be performed. This will prevent attackers from exploiting the vulnerability via the affected endpoint.

What

Sub2API is an AI API gateway platform designed to distribute and manage API quotas from AI product subscriptions. A vulnerability in versions prior to 0.1.85 is a Password Reset Poisoning (Host Header / Forwarded Header trust issue), which allows attackers to manipulate the password reset link. Attackers can exploit this flaw to inject their own domain into the password reset link, leading to the potential for account takeover. The vulnerability has been fixed in version v0.1.85. If upgrading is not immediately possible, users can mitigate the vulnerability by disabling the "forgot password" feature until an upgrade to a patched version can be performed. This will prevent attackers from exploiting the vulnerability via the affected endpoint.

Why

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

What

Sub2API is an AI API gateway platform designed to distribute and manage API quotas from AI product subscriptions. A vulnerability in versions prior to 0.1.85 is a Password Reset Poisoning (Host Header / Forwarded Header trust issue), which allows attackers to manipulate the password reset link. Attackers can exploit this flaw to inject their own domain into the password reset link, leading to the potential for account takeover. The vulnerability has been fixed in version v0.1.85. If upgrading is not immediately possible, users can mitigate the vulnerability by disabling the "forgot password" feature until an upgrade to a patched version can be performed. This will prevent attackers from exploiting the vulnerability via the affected endpoint.

Why

The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may bypass an access boundary or take over an account.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Encoding or Escaping of Output → bypass an access boundary or take over an account
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Not a CVSS 4.0 base metric
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-116 ↗

CWE-116: Improper Encoding or Escaping of Output. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U

Common Vulnerability Scoring System 4.0: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.ATNoneAttack requirements: No additional deployment or execution condition is required.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.VCHighVulnerable-system confidentiality: A successful attack can cause a major loss.VIHighVulnerable-system integrity: A successful attack can cause a major loss.VANoneVulnerable-system availability: No direct loss is represented by this metric.SCNoneSubsequent-system confidentiality: No direct loss is represented by this metric.SINoneSubsequent-system integrity: No direct loss is represented by this metric.SANoneSubsequent-system availability: No direct loss is represented by this metric.
Post-exploitation / living off the land
Stolen credentials, tokens and legitimate administration functions may provide continued access without deploying a large custom toolset.
NetworkUnauthenticatedCWE-116
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

Cyber Security Agency of Singapore · English · CSA-SB-20260304Security Bulletin 4 Mar 2026

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 4 Mar 2026, published on 4 March 2026. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2026-006432Sub2APIにおけるエンコードおよびエスケープに関する脆弱性

Sub2APIは、AI製品のサブスクリプションからのAPIクォータを配布および管理するために設計されたAI APIゲートウェイプラットフォームです。バージョン0.1.85以前には、パスワードリセットポイズニング(ホストヘッダー/転送ヘッダーの信頼の問題)という脆弱性が存在し、攻撃者がパスワードリセットリンクを操作できる可能性がありました。攻撃者はこの脆弱性を悪用して、自分のドメインをパスワードリセットリンクに注入し、アカウント乗っ取りを引き起こす危険性があります。この脆弱性はバージョンv0.1.85で修正されています。すぐにアップグレードできない場合は、修正済みバージョンへのアップグレードが行われるまで、「パスワードを忘れた」機能を無効にすることで脆弱性を緩和することが可能です。これにより、影響を受けるエンドポイントを介した攻撃者の悪用を防止できます。

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Mitigation available
Affected
sub2api: < 0.1.85
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Apply the mitigation in the linked authoritative guidance while planning the vendor's permanent fix.
Workaround
A mitigation or workaround reference is available from the source linked below; validate it against the affected product and version.
04

Evidence and provenance

Published 26 Feb 2026 · Last source change 26 Feb 2026, 14:53 UTC · CWE-116 · Improper Encoding or Escaping of Output

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2026-8782
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-27812 · cve.blacktree.nl