CVE-2021-3129
CVE-2021-3129 is a security flaw in Laravel Ignition. Attackers can run their own code on Laravel Ignition from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 18 Sep 2023, and says ransomware gangs have used it.[1]
Laravel Ignition is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff.
Description
CISA calls it a file upload in Laravel Ignition. In its words: “Laravel Ignition contains a file upload vulnerability that allows unauthenticated remote attackers to execute malicious code due to insecure usage of file_get_contents() and file_put_contents().”[1]
The CVE record adds: “Ignition before 2.5.2, as used in Laravel and other products, allows unauthenticated remote attackers to execute arbitrary code because of insecure usage of file_get_contents() and file_put_contents(). This is exploitable on sites using debug mode with Laravel before 8.4.2.”[2]
It scores 9.8 out of 10 on the Common Vulnerability Scoring System, which rates it critical, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it. CISA names the product as Laravel Ignition.
Most families won’t have Laravel Ignition; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 18 Sep 2023, 979 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 9 Oct 2023 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at over 99%. That’s in the top 1% of the flaws it scores.[3]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Laravel Ignition is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 9 Oct 2023 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 9.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at over 99%.[3] |
See also
Other Laravel flaws
- CVE-2025-54068, Laravel Livewire: code injection ·
- CVE-2018-15133, Laravel Framework: deserialization of untrusted data ·
Similar flaws
- CVE-2026-111357, Ivanti Connect Secure: missing authentication for critical function ·
- CVE-2026-97229, GitLab Community Edition and Enterprise Edition: integer overflow or wraparound ·
- CVE-2026-76418, Cisco Secure Firewall ASA Software and Cisco Secure FTD Software: unchecked return value to NULL pointer dereference ·
- CVE-2026-48356, Adobe Commerce and Magento: unrestricted upload of file with dangerous type ·
- CVE-2026-111497, Google Brotli: unchecked return value ·
Added the same day
- CVE-2022-22265, Samsung Mobile Devices: use-after-free ·
- CVE-2017-6884, Zyxel EMG2926 Routers: command injection ·
- CVE-2014-8361, Realtek SDK: improper input validation ·
Every Laravel flaw on CISA’s list · Everything added in September 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Laravel Ignition File Upload Vulnerability”. Known Exploited Vulnerabilities Catalog, added 18 Sep 2023.
- ^ National Institute of Standards and Technology. “CVE-2021-3129 Detail”. National Vulnerability Database, published 12 Jan 2021.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.999, percentile 100.0, 31 Oct 2026.
- CVE Program. “CVE-2021-3129”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.