Fluid Attacks Database

Description

AIOHTTP has HTTP response splitting via \r in reason phrase

Summary

An attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits.

Impact

In the unlikely situation that an application allows untrusted data to be used in the response's reason parameter, then an attacker could manipulate the response to send something different from what the developer intended.

Patch: https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b

Mitigation

Update Impact

Minimal update. May introduce new vulnerabilities or breaking changes.

Ecosystem	Package	Affected version	Patched versions
pypi	aiohttp	>=0 <3.13.4	3.13.4
debian 11	python-aiohttp	=3.7.4-1 \|\| =3.7.4-1+deb11u1 \|\| >=0 <3.7.4-1+deb11u2	3.7.4-1+deb11u2
debian 12	python-aiohttp	=3.10.0-1 \|\| =3.10.1-1 \|\| =3.10.10-1 \|\| =3.10.10-2 \|\| =3.10.11-1 \|\| =3.10.3-1 \|\| =3.10.3-2 \|\| =3.10.3-3 \|\| =3.10.4-1 \|\| =3.10.5-1 \|\| =3.10.6-1 \|\| =3.10.8-1 \|\| =3.11.15-1 \|\| =3.11.16-1 \|\| =3.12.15-1 \|\| =3.13.0-1 \|\| =3.13.1-1 \|\| =3.13.3-1 \|\| =3.13.3-2 \|\| =3.13.3-3 \|\| =3.13.5-1 \|\| =3.8.4-1 \|\| =3.8.4-1+deb12u1 \|\| =3.8.5-1 \|\| =3.8.6-1 \|\| =3.9.1-1 \|\| =3.9.5-1	-
debian 13	python-aiohttp	=3.11.16-1 \|\| =3.11.16-1+deb13u1 \|\| =3.12.15-1 \|\| =3.13.0-1 \|\| =3.13.1-1 \|\| =3.13.3-1 \|\| =3.13.3-2 \|\| =3.13.3-3 \|\| =3.13.5-1	-
debian 14	python-aiohttp	=3.11.16-1 \|\| =3.12.15-1 \|\| =3.13.0-1 \|\| =3.13.1-1 \|\| =3.13.3-1 \|\| =3.13.3-2 \|\| =3.13.3-3 \|\| >=0 <3.13.5-1	3.13.5-1

Aliases

1. CVE-2026-345192. NVD-2026-345193. OSV-2026-345194. OSV-DEBIAN-2026-345195. GHSA-mwh4-6h8g-pg8w6. GCVE-2026-345197. SECURITY-TRACKER-CVE-2026-34519

References

1. https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mwh4-6h8g-pg8w2. https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b3. https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4

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