6.9

CVE-2026-116585: Go JOSE: Panic during CBC-HMAC processing

Awaiting analysis
AliasesUBUNTU-CVE-2026-116585GHSA-4w3g-jfj2-cw2qCGA-2723-c22m-2chg
Published 26-10-2026Last modified 31-10-2026

Vulnerability summary

CVE-2026-116585 is a medium (CVSS 6.9) Improper Validation of Array Index vulnerability in go-jose. EPSS estimates a 0.26% chance of exploitation in the next 30 days, higher than 18.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 6.9, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.9/10
010
Medium · v4.0 (CVE.org)
EPSS score
0.26%
0%100%
Low · Change unavailable
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 26-10-2026
    PublishedVulnerability first disclosed.
  2. 31-10-2026
    Last modifiedVulnerability information updated.

Description

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 validation allows the empty buffer to be indexed, causing a panic and denial of service. Applications that decrypt attacker-controlled ciphertext with one of these content-encryption algorithms are affected. This issue is fixed in version 4.1.5.

CVSS metrics

7 scores · 7 sources · 1 version

EPSS trend

Probability

0.26%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

27-10-202604-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Chainguard200 products
  • amazon-ssm-agentAll versions (No fix recorded) | < 3.3.5708.0-r0
  • amazon-ssm-agent-ecs-execAll versions (No fix recorded) | < 3.3.5708.0-r0
  • amazon-ssm-agent-ecs-exec-fipsAll versions (No fix recorded) | < 3.3.5708.0-r0
  • amazon-ssm-agent-fipsAll versions (No fix recorded) | < 3.3.5708.0-r0
  • apkoAll versions (No fix recorded)

1 vendor · 200 products · Showing 200 of 516

References

12 links
Show all 12 references