CVE-2026-68511
Paaster: TOCTOU race condition defeats the 'burn after reading' guarantee on view-once pastes
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| paaster WardPearce |
< 3.3.0 (affected) | CNA: GitHub_M |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 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 | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/WardPearce/paaster/security/advisories/GHSA-xh42-5mjw-2f4vCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/WardPearce/paaster/releases/tag/v3.3.0CNA: GitHub_M · x_refsource_MISC
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