CVE-2023-27539

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

1.08% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 62.8% of scored records. A rank, not a probability.

NVD base score

5.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

NVD analysis status

Analyzed. NVD last modified this record on 2026-06-17.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-01-09 00:33Z1 YR AGO

Last updated

2025-01-09 21:24Z1 YR AGO

Reserved

2023-03-02

Assigning CNA

hackerone

Record state

PUBLISHED

Severity

Medium (CVSS 5.3)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Weaknesses

• CWE-1333Inefficient Regular Expression ComplexityBase

Data version

5.1

Document digest

2e377076310be44be7fa03ff7d54d46a9d7410475307109f900fdf301a0631ea

• discuss.rubyonrails.orghttps://discuss.rubyonrails.org/t/cve-2023-27539-possible-denial-of-service-vulnerability-in-racks-header-parsing/82466
• github.comhttps://github.com/advisories/GHSA-c6qg-cjj8-47qp
• github.comhttps://github.com/rack/rack/commit/231ef369ad0b542575fb36c74fcfcfabcf6c530c
• github.comhttps://github.com/rack/rack/commit/ee7919ea04303717858be1c3f16b406adc6d8cff
• lists.debian.orghttps://lists.debian.org/debian-lts-announce/2023/04/msg00017.html
• security.netapp.comhttps://security.netapp.com/advisory/ntap-20231208-0016/
• www.debian.orghttps://www.debian.org/security/2023/dsa-5530