CVE-2023-38522: apache software foundation apache traffic server HTTP Request/Response Smuggling
Vulnerability summary
CVE-2023-38522 is a high (CVSS 7.5) HTTP Request/Response Smuggling vulnerability in apache software foundation apache traffic server. EPSS estimates a 0.99% chance of exploitation in the next 30 days, higher than 61.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2Timeline
- 26-07-2024PublishedVulnerability first disclosed.
- 03-11-2025Last modifiedVulnerability information updated.
Description
Apache Traffic Server accepts characters that are not allowed for HTTP field names and forwards malformed requests to origin servers. This can be utilized for request smuggling and may also lead cache poisoning if the origin servers are vulnerable. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.10, from 9.0.0 through 9.2.4. Users are recommended to upgrade to version 8.1.11 or 9.2.5, which fixes the issue.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS trend
Probability
0.99%
Chance of exploitation in the next 30 days
Percentile
62%
Versus all other CVEs
30-day change
0.00 pp
From 0.99% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Apache1 product
- traffic_server≥ 8.0.0, < 8.1.11 | ≥ 9.0.0, < 9.2.5
Apache software foundation1 product
- apache traffic server≥ 8.0.0, ≤ 8.1.10 | ≥ 9.0.0, ≤ 9.2.4
Debian1 product
- trafficserver< 9.2.5+ds-0+deb12u1
Ubuntu1 product
- trafficserverAll versions (No fix recorded)
4 vendors · 4 products