CVE-2026-53776
Perry < 0.5.1166 JWT Expiration Bypass via verify_decode
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
9.3
Perry < 0.5.1166 JWT Expiration Bypass via verify_decode
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.
- Record
CVE-2026-53776- CVSS 4.0
- 9.3 Critical
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 - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-613
- Updated
- 2026-11-02
EUVDEUVD-2026-37126
9.3
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.
- Record
EUVD-2026-37126- CVSS 4.0
- 9.3 Critical
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 - Updated
- 2026-11-02
NVD
9.3
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.
- Record
CVE-2026-53776- CVSS 4.0
- 9.3 Critical
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 - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-613
- Updated
- 2026-11-02
OSV
9.3
Perry < 0.5.1166 JWT Expiration Bypass via verify_decode
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.
- Record
CVE-2026-53776- CVSS 4.0
- 9.3 Critical
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 - Weakness
- CWE-613
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-53776 is a critical vulnerability (CVSS 9.3) in Perryts Perry, published June 16, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.36%, the 29th percentile. No source names a fixed version.
References
github.com/PerryTS/perry/releases/v0.5.1166
github.com/PerryTS/perry/security/advisories/GHSA-5324-c68v-8w62
vulncheck.com/advisories/perry-jwt-expiration-bypass-via-verify-decode
github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53776.json
nvd.nist.gov/vuln/detail/CVE-2026-53776
github.com/PerryTS/perry