Security research · CVE-2026-116585

Go JOSE: Panic during CBC-HMAC processing

Q: Which versions are affected?

Compare what you have installed with 0 → 3.0.5, 0 → 4.1.5, <= 3.0.5, < 4.1.5. Compare the installed version with the linked vendor advisory before you change production.

Q: What should an analyst verify?

CWE-129: Improper Validation of Array Index. EPSS 0.26%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Published Oct 26, 2026 · catalog updated Oct 31, 2026 · Go JOSE: Panic during

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-116585. EPSS is 0.26%. Act only if a listed version of Go JOSE: Panic during is installed.

Gaps on this record

The stored product name is a package slug. The name on this page is taken from the title (Go JOSE: Panic during).
No vendor fix or required action is stored. Compare the linked advisory before you change production.

Severity: Medium6.9
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.26%
Remediation: Version ranges on file
Affected products: Go github.com/go-jose/go-jose/v3 · Go github.com/go-jose/go-jose/v4 · go github.com/go-jose/go-jose/v3 · go github.com/go-jose/go-jose/v4 · golang github.com

### Summary Decrypting a ciphertext with "A128CBC-HS256", "A192CBC-HS384", or "A256CBC-HS512" can result in a panic on untrusted input. Note this advisory is the same as https://github.com/go-jose/go-jose/security/advisories/GHSA-6mp9-8xrw-74r4. ### Details Insufficient validation of parameters can lead to attempting to index into an empty buffer. See https://github.com/go-jose/go-jose/pull/292. ### Workarounds If the application does not require the CBC-HMAC modes for content encryption, and is using github.com/go-jose/go-jose/v4, do not include them in the list of ContentEncryption algorithms passed to ParseEncrypted / ParseEncryptedJSON / ParseEncryptedCompact. ### Impact Denial of service vulnerability. Any application which decrypts untrusted ciphertexts with the indicated algorithms is affected. ### Acknowledgements Thanks to Joshua Rogers of AISLE Research for reporting this problem.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Go github.com/go-jose/go-jose/v30 → 3.0.5
Go github.com/go-jose/go-jose/v40 → 4.1.5
go github.com/go-jose/go-jose/v3<= 3.0.5
go github.com/go-jose/go-jose/v4< 4.1.5
golang github.comversion unspecified

How to fix CVE-2026-116585

Upgrade
CVE-2026-116585 lists a fix boundary at 3.0.5. Compare the installed build with that boundary before you change production.
Version check
Affected <= 3.0.5
Advisory
Open the cve_org record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-116585. EPSS is 0.26%. Act only if a listed version of Go JOSE: Panic during is installed.

Which versions are affected?

Compare what you have installed with 0 → 3.0.5, 0 → 4.1.5, <= 3.0.5, < 4.1.5. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-129: Improper Validation of Array Index. EPSS 0.26%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Repository · github.com

Timeline

Detection, updates, and resolution for this record.

Oct 28, 2026 · GitHub Advisory Database
Detected
### Summary Decrypting a ciphertext with "A128CBC-HS256", "A192CBC-HS384", or "A256CBC-HS512" can result in a panic on untrusted input. Note this advisory is the same as https://github.com/go-jose/go-jose/security/advisories/GHSA-6mp9-8xrw-74r4. ### Details Insufficient validation of parameters can lead to attempting to index into an empty buffer. See https://github.com/go-jose/go-jose/pull/292. #
Oct 28, 2026 · GitHub Advisory Database
Fix available
github.com/go-jose/go-jose/v4 fixed in 4.1.5
Oct 28, 2026 · GitHub Advisory Database
Fix available
github.com/go-jose/go-jose/v4 fixed in 4.1.5
Oct 28, 2026 · GitHub Advisory Database
Fix available
github.com/go-jose/go-jose/v3 fixed in 3.0.5
Oct 28, 2026 · GitHub Advisory Database
Updated
### Summary Decrypting a ciphertext with "A128CBC-HS256", "A192CBC-HS384", or "A256CBC-HS512" can result in a panic on untrusted input. Note this advisory is the same as https://github.com/go-jose/go-jose/security/advisories/GHSA-6mp9-8xrw-74r4. ### Details Insufficient validation of parameters can lead to attempting to index into an empty buffer. See https://github.com/go-jose/go-jose/pull/292. #
Oct 31, 2026 · NIST NVD
Updated
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.5, decrypting untrusted JWE ciphertext with A128CBC-HS256, A192CBC-HS384, or A256CBC-HS512 can pass an empty ciphertext buffer to CBC-HMAC unpadding. Insufficient valida

Sources

CVE.orgVulnerability recordCVE-2026-116585
Official CVE identifier
cve.org
GitHub Advisory DatabasePackage advisoryGHSA-4w3g-jfj2-cw2q
GitHub Advisory Database record mirrored by OSV.
github.com
GitLab Advisory DatabasePackage advisoryCVE-2026-116585
Decrypting a ciphertext with "A128CBC-HS256", "A192CBC-HS384", or "A256CBC-HS512" can result in a panic on untrusted input. Note this advisory is the same as https://github.com/go-jose/go-jose/security/advisories/GHSA-6mp9-8xrw-74r4 .
advisories.gitlab.com
Go Vulnerability DatabasePackage advisoryGHSA-4w3g-jfj2-cw2q
Go JOSE: Panic during CBC-HMAC processing
osv.dev
NIST NVDVulnerability recordCVE-2026-116585
Go JOSE provides an implementation of the Javascript Object Signing and Encryption set of standards in Go, including support for JSON Web Encryption (JWE), JSON Web Signature (JWS), and JSON Web Token (JWT) standards. Prior to 4.1.5, decrypting untrusted JWE ciphertext with A128C
nvd.nist.gov
OpenSSF OSV / OSV ScannerPackage advisoryGHSA-4w3g-jfj2-cw2q
Go JOSE: Panic during CBC-HMAC processing
osv.dev

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

Go Vulnerability DatabaseOct 31, 2026
NIST NVDOct 31, 2026
GitLab Advisory DatabaseOct 30, 2026
GitHub Advisory DatabaseOct 30, 2026
OpenSSF OSV / OSV ScannerOct 30, 2026
CVE.orgOct 29, 2026

Priority score

11/100

Evidence confidence: High

Several independent sources name this vulnerability.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity10/15
Public exploit0/10
Internet exposure0/10
Product prevalence0/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

Medium

CVSS severity
6.9 v4.0
Technical impact. Separate from exploitation likelihood.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:
EPSS probability
0.26% · p18.31%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Version ranges on file
Affected version ranges suggest a fixed boundary. Verify against the vendor advisory for your release.

Stacks

Weakness

CWE-129
Improper Validation of Array Index
MITRE definition

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