Paaster: TOCTOU race condition defeats the 'burn after reading' guarantee on view-once pastes
Summary
| CVE | CVE-2026-68511 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-11 22:17:30 UTC |
| Updated | 2026-11-12 22:18:51 UTC |
| Description | Paaster is a pastebin application. Prior to version 3.3.0, Paaster's "view once" (burn-after-reading) paste mode can be bypassed with concurrent requests. The check that's supposed to enforce single-use is a plain read followed by a separate write, with no atomicity, so multiple simultaneous requests can all see the paste as "not yet read" and all successfully retrieve it. This issue has been patched in version 3.3.0. |
Risk And Classification
Primary CVSS: v4.0 6.3 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-362 | CWE-362 CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | DECLARED | 6.3 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
LowIntegrity
NoneAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | WardPearce | Paaster | affected < 3.3.0 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/WardPearce/paaster/releases/tag/v3.3.0 | [email protected] | github.com | |
| github.com/WardPearce/paaster/security/advisories/GHSA-xh42-5mjw-2f4v | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.