Security readout for executives and security teams
Plain-English summary
A flaw in Laravel Socialite’s Facebook login handling can let an unauthenticated attacker reuse a captured, still-valid Facebook identity token to access the token owner’s account. The attacker must obtain a token issued for the same Facebook App ID, but successful replay could compromise account confidentiality, integrity, and availability.
Executive priority
Treat as an urgent identity-control issue for internet-facing applications using this Facebook login path. Identify exposure immediately and prioritize the upstream patch. Applications not using Laravel Socialite’s Facebook provider are not shown by the supplied evidence to be affected.
Technical view
FacebookProvider.php validates an OIDC token’s signature, audience, and issuer, but getUserByOIDCToken() lacks session-bound nonce validation. Consequently, userFromToken() may accept a replayed, unexpired id_token for the same Facebook App ID. The issue is classified as CWE-294 and scored CVSS 4.0 9.2, with high attack complexity.
Likely exposure
Exposure is limited to applications using Laravel Socialite’s affected Facebook provider and accepting OIDC id_tokens through userFromToken(). Exploitation requires possession of a valid, unexpired token for the application’s Facebook App ID. The supplied affected-version value, "0", does not establish a usable release range.
Exploitation context
The CVE is not listed as KEV in the supplied data, and no cited source establishes active exploitation. Exploitation is remotely reachable without prior authentication, but requires capturing an appropriate victim token, consistent with the CVSS high-complexity rating. Evidence supports replay risk, not widespread exploitation.
Researcher notes
The strongest technical evidence is the upstream pull request and patch commit. The supplied CVE data reports only affected version "0", so exact vulnerable and fixed releases remain unclear. Validate release mapping against current vendor guidance. No evidence supplied here supports claims of public exploitation or inclusion in CISA KEV.
Mitigation direction
- Review Laravel Socialite guidance and deploy a release containing patch commit caf714f55d51ab0d914b40033d8b0f489d6219cc.
- Temporarily disable the affected Facebook token-login flow if a verified patched release cannot be deployed promptly.
- Review recent Facebook authentication activity and invalidate application sessions associated with suspected token replay.
Validation and detection
- Inventory applications using Laravel Socialite’s Facebook provider and userFromToken() handling.
- Confirm deployed Socialite code includes the nonce-validation changes from the cited patch commit.
- Test that a previously accepted token cannot authenticate outside its originating session context.
- Review authentication logs for repeated token use or unexpected access to established accounts.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-294: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-73683 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9VulnCheckVulnerability scoring details
Base CVSS 4.0 score
9.2CriticalVector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- Pull RequestCVE reference, VulnCheck · product
- Patch CommitCVE reference, VulnCheck · patch
- Product RepositoryCVE reference, VulnCheck · vendor-advisory
- https://www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authentication-bypass-via-nonce-replayCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Authentication Bypass by Capture-replay
Authentication Bypass by Capture-replay represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.