Php guzzlehttp psr7: Prior to 2.12.3, Uri::assertValidHost() does not reject URI host components containing authority
Affects php-guzzlehttp-psr7Source GCVE Database
Not known to be exploited · CVSS 4.2 Medium · fixed in 2.12.3 : update php-guzzlehttp-psr7 when convenient.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.12.3
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSphp-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@2.8.0-2?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10php-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@2.7.1-1?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSphp-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@2.6.2-1?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSphp-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@1.8.3-1ubuntu0.1~esm1?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu 20.04 LTSphp-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@1.4.2-0.1+deb10u2build0.20.04.1?arch=source&distro=focalOther threats | Affected
| Fixed in– |
Ubuntu 16.04 LTSphp-guzzlehttp-psr7pkg:deb/ubuntu/php-guzzlehttp-psr7@1.2.2-1ubuntu1?arch=source&distro=xenialOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to guzzlehttp/psr7 version 2.12.3 or later, where this vulnerability is resolved. No other mitigation or temporary workaround is indicated.
Description
A vulnerability exists in the guzzlehttp/psr7 PHP library prior to version 2.12.3 in the Uri::assertValidHost() function. This function does not properly reject URI host components containing authority delimiters, embedded ports, or malformed IPv6 brackets. Consequently, the Uri::getHost() method may return an incorrect host value that differs from the actual URI authority, which could affect security or routing decisions. The issue is fixed in version 2.12.3.
References
- ubuntu.com/security/CVE-2026-59882 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-59882 (opens in a new tab)
- github.com/guzzle/psr7/security/advisories/GHSA-c2w2-prh8-qm98 (opens in a new tab)
- github.com/guzzle/psr7/pull/811 (opens in a new tab)
- github.com/guzzle/psr7/commit/ddd64f17d4cc1f7e5ffe6fd2c989ec7221712580 (opens in a new tab)
- github.com/guzzle/psr7/releases/tag/2.12.3 (opens in a new tab)