What is CVE-2026-73683?

CVE-2026-73683 is Laravel Socialite Facebook Provider Authentication Bypass via Nonce Replay. The supplied enrichment data classifies it as Auth Bypass mapped to CWE-294 CWE-294.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Active exploitation is not confirmed from current sources for CVE-2026-73683. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

No. CVE-2026-73683 is not listed in CISA KEV in the supplied enrichment data. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

Is there a public exploit?

A public PoC is not confirmed from current sources for CVE-2026-73683. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS, identity provider logs, authentication audit logs where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2026-73683 using CVSS 8.1, EPSS 0%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

No public threat actor linkage is confirmed from current sources. Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Prioritize based on EPSS, PoC availability, and external exposure. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

highAuth Bypass

CVE-2026-73683

CVE-2026-73683 — Laravel Socialite Facebook Provider Authentication Bypass via Nonce Replay

Laravel Socialite's Facebook provider contains an authentication bypass vulnerability that allows unauthenticated attackers to replay captured OIDC id_tokens by exploiting the missing nonce claim validation in the getUserByOIDCToken() function within FacebookProvider.php. Attackers who obtain a valid, unexpired id_token issued for the same Facebook App ID can submit the captured token to the backend userFromToken() endpoint, bypassing authentication controls because signature, aud, and iss checks pass while no session-bound nonce comparison is performed, resulting in unauthorized access to victim accounts.

Published Aug 14, 2026Updated Aug 14, 2026Sources: NVD, Laravel (CNA), GitHub, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Unreported

no source claims exploitation

EPSS

ahead of 0% of scored CVEs

Affects

Laravel

Socialite

CVSS base

8.1

high · 2 sources

Remediation

The vendor's own words where we have them.

Upgrade Socialite to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Prioritize based on EPSS, PoC availability, and external exposure.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
Laravel	Socialite	0 to < 5.29.0	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

High

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
8.1	CVSS 3.1	high	2.2	5.9	NVD, Laravel (CNA)
9.2	CVSS 4.0	critical	—	—	Laravel (CNA)

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-294 · Authentication Bypass by Capture-replay

Gain Privileges or Assume Identity

Mitigation: Utilize some sequence or time stamping functionality along with a checksum which takes this into account in order to ensure that messages can be parsed only once.

Weakness & attack patterns

CWE-294

Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.

CAPEC-555 · Remote Services with Stolen CredentialsCAPEC-644 · Use of Captured Hashes (Pass The Hash)CAPEC-94 · Man in the Middle AttackCAPEC-509 · KerberoastingCAPEC-60 · Reusing Session IDs (aka Session Replay)CAPEC-561 · Windows Admin Shares with Stolen CredentialsCAPEC-652 · Use of Known Kerberos CredentialsCAPEC-645 · Use of Captured Tickets (Pass The Ticket)CAPEC-102 · Session Sidejacking

T1558.003Steal or Forge Kerberos Tickets: Kerberoasting
T1021Remote Services
T1114.002Email Collection: Remote Email Collection

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable Socialite.

web/proxy/WAF logsapplication logsnetwork IDS/IPSidentity provider logsauthentication audit logs

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 8.1 (AV:N)
Aug 14, 2026 · NVD
Initial · CVE published
Aug 14, 2026 · NVD

References

4 on the record

github.com/laravel/socialite
Exploit, Third Party Advisory
github.com/laravel/socialite/commit/caf714f55d51ab0d914b40033d8b0f489d6219cc
Exploit, Third Party Advisory
github.com/laravel/socialite/pull/789
Exploit, Third Party Advisory
www.vulncheck.com/advisories/laravel-socialite-facebook-provider-authentication-bypass-via-nonce-replay
Vendor Advisory

Elsewhere on this site

Laravelevery CVE for this vendor
Auth Bypasssame class
CWE-294other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2026-73683 is Laravel Socialite Facebook Provider Authentication Bypass via Nonce Replay, a high vulnerability affecting Socialite from Laravel. The current evidence does not list it in CISA KEV, and the exploit status is: Active exploitation is not confirmed from current sources for CVE-2026-73683. Public exploit evidence is: A public PoC is not confirmed from current sources for CVE-2026-73683. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 8.1 describes technical severity, while EPSS 0% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.