CVE-2026-53776 json
Perry < 0.5.1166 JWT Expiration Bypass via verify_decode
published 2026-06-16 4 mo ago modified 2026-11-08 20 h ago also EUVD-2026-37126
- cvss
- 9.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
Summary
Perry before 0.5.1166 contains a JWT validation vulnerability that allows remote attackers to bypass token expiration by exploiting the unconditional setting of validate_exp = false in the verify_decode helper within the stdlib JWT verification path. Attackers in possession of a previously issued bearer token can present expired tokens to any jwt.verify() call and retain authenticated access indefinitely, bypassing force-expired sessions such as user logout or administrative revocation.
Patch / fix
- PerryTS perry 0.5.1166
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 4 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N |
| CNA | 3.1 | 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N |
| CNA | 4.0 | 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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 |
Affected products
- PerryTS perry
Classification
- Weakness
-
- CWE-613 DEPRECATED: Insufficient Session Expiration
References
-
github.com
/PerryTS/perry/security/advisories/GHSA-5324-c68v-8w62
vendor-advisory
-
github.com
/PerryTS/perry/releases/v0.5.1166
release-notes
-
vulncheck.com
/advisories/perry-jwt-expiration-bypass-via-verify-decode
third-party-advisory
Sources
- CVE List CVE-2026-53776
- NVD CVE-2026-53776
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