Bug bounty reports15,219
Publicly disclosed HackerOne reports, with the platform's own outcome and severity.
| Report | Status | Weakness | Severity | Disclosed | Bounty | Votes |
|---|---|---|---|---|---|---|
| File upload XSS (Java applet) on http://slackatwork.com/#97657 | Valid | Command and Code Injection | – | 2015-11-11 | $200 | 1 |
| an xss issue in https://hunter22.slack.com/help/requests/793043#116419 | Valid | Cross-site Scripting | – | 2016-04-30 | $100 | 1 |
| flash content type sniff vulnerability in api.slack.com#3455 | Valid | Cross-Site Request Forgery | – | 2014-04-08 | – | 2 |
| Stored XSS in slack.com (integrations)#10297 | Valid | Cross-site Scripting | – | 2014-05-29 | – | 2 |
| Content spoofing at Stripe Integrations#21248 | Valid | Misconfiguration and Insecure Design | – | 2014-08-25 | $100 | 2 |
| HTTP Strict Transport Policy not enabled on newly made accounts#26763 | Valid | Misconfiguration and Insecure Design | – | 2014-10-03 | – | 2 |
| Logout any user of same team#54610 | Valid | Cross-Site Request Forgery | – | 2015-05-05 | – | 2 |
| Self-XSS in posts by formatting text as code#89505 | Valid | Cross-site Scripting | – | 2015-11-10 | – | 2 |
| Reflected Self-XSS in Slack#97683 | Valid | Cross-site Scripting | – | 2015-11-10 | – | 2 |
| CSRF on add comment section#2638 | Valid | Cross-Site Request Forgery | – | 2014-04-12 | – | 3 |
| Stored XSS in Channel Chat#2652 | Valid | Cross-site Scripting | – | 2014-05-21 | – | 3 |
| Duplicate of #4550#4638 | Valid | No weakness recorded | – | 2014-05-21 | – | 3 |
| Team admin can change unauthorized team setting (require_at_for_mention)#46747 | Valid | Access Control | – | 2015-04-30 | $200 | 3 |
| Team admin can change unauthorized team setting (allow_message_deletion)#46750 | Valid | Access Control | – | 2015-05-30 | $100 | 3 |
| Team admin can add billing contacts#47940 | Valid | Access Control | – | 2015-04-03 | $200 | 3 |
| Reflective XSS can be triggered in IE#2497 | Valid | Cross-site Scripting | – | 2015-03-15 | $150 | 4 |
| Stored XSS in username.slack.com#2625 | Valid | Cross-site Scripting | – | 2014-08-07 | – | 4 |
| csrf#2635 | Valid | Cross-Site Request Forgery | – | 2014-04-06 | – | 4 |
| Reflected Xss#2777 | Valid | Cross-site Scripting | – | 2014-05-19 | $500 | 4 |
| Stored XSS#2926 | Valid | Cross-site Scripting | – | 2014-04-06 | – | 4 |
| Content Spoofing all Integrations in https://team.slack.com/services/new/#22093 | Valid | Misconfiguration and Insecure Design | – | 2014-09-03 | $200 | 4 |
| Stored XSS in Slack (weird, trial and error)#96337 | Valid | Cross-site Scripting | – | 2015-11-10 | – | 4 |
| Executing scripts on slack-files.com using SVG#100565 | Valid | Cross-site Scripting | – | 2016-02-18 | – | 4 |
| Trick make all fixed open redirect links vulnerable again#104087 | Valid | Open Redirect | – | 2016-05-22 | $1,000 | 4 |
| URL redirection flaw#2622 | Valid | Open Redirect | – | 2014-08-30 | – | 5 |
| CSRF vulnerability on https://sehacure.slack.com/account/settings#2628 | Valid | Cross-Site Request Forgery | – | 2014-07-26 | – | 5 |
| Stored XSS in Slack.com#6002 | Valid | Cross-site Scripting | – | 2015-03-09 | – | 5 |
| SSRF on https://whitehataudit.slack.com/account/photo#14127 | Valid | Command and Code Injection | – | 2014-12-21 | – | 5 |
| Password Policy issue (Weak Protect)#17160 | Valid | Misconfiguration and Insecure Design | – | 2014-09-04 | – | 5 |
| File upload over private IM channel#143903 | Valid | Access Control | – | 2016-07-13 | – | 5 |
| Generate new Test token#147544 | Valid | Authentication | – | 2016-09-15 | $100 | 5 |
| Email information leakage for certain addresses#169992 | Valid | Information Disclosure | – | 2016-10-31 | $400 | 5 |
| Stored XSS on this link https://sehacure.slack.com/help/requests/#2639 | Valid | Cross-site Scripting | – | 2014-08-30 | – | 6 |
| State parameter missing on google OAuth#2688 | Valid | Cross-Site Request Forgery | – | 2014-04-06 | – | 6 |
| a stored xss in slack integration https://onerror.slack.com/services/import#33018 | Valid | Cross-site Scripting | – | 2016-05-22 | $500 | 6 |
| RC4 cipher suites detected on status.slack.com#99157 | Valid | Misconfiguration and Insecure Design | – | 2016-11-18 | – | 6 |
| CSRF - Add optional two factor mobile number#155774 | Valid | Cross-Site Request Forgery | – | 2016-08-17 | $500 | 7 |
| Broken Authentication (including Slack OAuth bugs)#2559 | Valid | Misconfiguration and Insecure Design | – | 2014-08-30 | – | 8 |
| Stored XSS in www.slack-files.com#2617 | Valid | Cross-site Scripting | – | 2014-05-23 | – | 8 |
| Stored XSS in Slackbot Direct Messages#4561 | Valid | Cross-site Scripting | – | 2014-05-04 | – | 8 |
| Open Redirect login account#16718 | Valid | Open Redirect | – | 2014-08-25 | $100 | 8 |
| "a stored xss issue in share post menu"#148848 | Valid | Cross-site Scripting | – | 2017-06-25 | $500 | 8 |
| Data exports stored on S3 can be scraped easily#2746 | Valid | Authentication | – | 2014-12-09 | – | 9 |
| Stored XSS Found#9774 | Valid | Cross-site Scripting | – | 2014-06-01 | – | 9 |
| a stored xss issue in https://files.slack.com#149011 | Valid | Cross-site Scripting | – | 2017-06-25 | $500 | 9 |
| Possibility to freeze/crash the host system of all Slack Desktop users easily#392728 | Valid | Misconfiguration and Insecure Design | – | 2020-11-10 | – | 9 |
| Slack OAuth2 "redirect_uri" Bypass#2575 | Valid | Authentication | – | 2014-05-29 | – | 10 |
| Authentication bypass leads to sensitive data exposure (token+secret)#129918 | Valid | Authentication | – | 2016-10-19 | $2,000 | 10 |
| User can start call in a channel of an unpaid account#147369 | Valid | Access Control | – | 2016-09-15 | $100 | 10 |
| Creating Post on a restricted channel#151459 | Valid | Access Control | – | 2016-09-29 | – | 10 |
Status and severity are HackerOne's. “Access stated” is what the title says; “Access needed” and techniques come from CyberSIXT's analysis of the public report (549 analysed so far), which can be wrong. Data as of 2026-11-14.