[UPDATE] [high] Apache HTTP Server: Multiple vulnerabilities allow HTTP response splitting

highCVE-2023-25690 CVE-2023-27522

A remote, anonymous attacker can exploit multiple vulnerabilities in Apache HTTP Server to conduct a response splitting attack.

CSIRTS triage

vendor: Apache product: Apache HTTP ServerOther

What: Multiple vulnerabilities in Apache HTTP Server allow a remote, anonymous attacker to conduct an HTTP response splitting attack.
Who is affected: Remote users of Apache HTTP Server are affected by these vulnerabilities.
Urgency: Remediation is urgent due to the high severity of the vulnerabilities and potential for exploitation.
Action: Apply the latest patches for Apache HTTP Server.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: high
Published: 2026-07-24
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2023-0583

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Exploitation likely imminentCVE-2023-25690EPSS puts this in the most-targeted tier (83.8% 30-day exploitation probability). Prioritize alongside KEV items. Riskier than 100% of all scored CVEs.
Moderate exploitation riskCVE-2023-275222.1% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 80% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2023-25690	coverage & exploitation status	NVD · CVE.org
CVE-2023-27522	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

unknownNCSC-2026-0246 [1.00] [M/H] Vulnerabilities fixed in Adobe Experience Managerncsc-nl

Recent advisories for Apache HTTP Server

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

highCVE-2026-58154: Apache Traffic Server can write out of bounds or overflow integers while parsing MIME and HTTP…nvd · 2026-07-29
highCVE-2026-24033: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability…nvd · 2026-07-29
high[UPDATE] [high] Apache HTTP Server: Multiple vulnerabilitiescert-bund · 2026-07-28
high[UPDATE] [high] Apache HTTP Server: Multiple vulnerabilitiescert-bund · 2026-07-28
high[UPDATE] [high] Apache HTTP Server: Multiple vulnerabilitiescert-bund · 2026-07-28
high[UPDATE] [high] Apache HTTP Server: Multiple vulnerabilitiescert-bund · 2026-07-28