The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to c
The (1) S_reghop3, (2) S_reghop4, and (3) S_reghopmaybe3 functions in regexec.c in Perl before 5.24.0 allow context-dependent attackers to cause a denial of service (infinite loop) via crafted utf-8 data, as demonstrated by "a\x80."
Noroxi analysis
No Noroxi analysis for this record yet
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We use this product, ask for help- Published
- May 25, 2016
- Updated
- Jun 16, 2026
- EPSS
- 2.6% · 84th percentile
- CWE
- CWE-20
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.6%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| perl | perl | cpe:2.3:a:perl:perl |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- fedoraproject fedora22
- perl perlup to 5.23.9 inclusive
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | perl | before 5.22.1-1 | 5.22.1-1 |
| Red Hat:hummingbird:1 | perl | before 0:5.42.2-524.hum1 | 0:5.42.2-524.hum1 |
| Red Hat:hummingbird:1 | perl-Attribute-Handlers | before 0:1.03-524.hum1 | 0:1.03-524.hum1 |
| SUSE:Linux Enterprise Desktop 12 SP1 | perl | before 5.18.2-11.1 | 5.18.2-11.1 |
| SUSE:Linux Enterprise Software Development Kit 11 SP4 | perl | before 5.10.0-64.80.1 | 5.10.0-64.80.1 |
Same product
perl: all recordsOther highest-scoring records for the same primary product.
- CVE-2012-6329The _compile function in Maketext.pm in the Locale::Maketext implementation in Perl before 5.17.7 does not properly handle backslashes and f49Plan
- CVE-2018-18311Perl before 5.26.3 and 5.28.x before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.43Plan
- CVE-2018-18312Perl before 5.26.3 and 5.28.0 before 5.28.1 has a buffer overflow via a crafted regular expression that triggers invalid write operations.43Plan
- CVE-2018-6913Heap-based buffer overflow in the pack function in Perl before 5.26.2 allows context-dependent attackers to execute arbitrary code via a lar42Plan
- CVE-2018-18314Perl before 5.26.3 has a buffer overflow via a crafted regular expression that triggers invalid write operations.41Plan
- CVE-2018-6797An issue was discovered in Perl 5.18 through 5.26.41Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| debian:perl | 5.22.1-1 · Debian:12 | Package registry (OSV) |
| red hat:perl | 0:5.42.2-524.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| red hat:perl-Attribute-Handlers | 0:1.03-524.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:perl | 5.10.0-64.80.1 · SUSE:Linux Enterprise Software Development Kit 11 SP4 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-20 · Improper Input ValidationCVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- Cross Zone ScriptingCAPEC-104likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Object Relational Mapping InjectionCAPEC-109likelihood: Low · High
- SQL Injection through SOAP Parameter TamperingCAPEC-110likelihood: High · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
ATT&CK techniques
- Obfuscated Files or InformationT1027
- Masquerading: Invalid Code SignatureT1036.001
- Steal Web Session CookieT1539
- Subvert Trust Controls: Code SigningT1553.002
- Impair Defenses:Impair Command History LoggingT1562.003
- Hijack Execution Flow:Dynamic Linker HijackingT1574.006
- Hijack Execution Flow:Path Interception by PATH Environment VariableT1574.007
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- lists.fedoraproject.org/pipermail/package-announce/2016-May/183592.html
- perl5.git.perl.org/perl.git/commitdiff/22b433eff9a1ffa2454e18405a56650f07b385b5
- www.openwall.com/lists/oss-security/2016/04/20/5
- www.openwall.com/lists/oss-security/2016/04/20/7
- www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- www.securityfocus.com/bid/86707
- bugzilla.redhat.com/show_bug.cgi?id=1329106
- h20566.www2.hpe.com/portal/site/hpsc/public/kb/docDisplay?docId=emr_na-c05240731
- rt.perl.org/Public/Bug/Display.html?id=123562
- security.gentoo.org/glsa/201701-75
- usn.ubuntu.com/3625-1/
- usn.ubuntu.com/3625-2/
Vendor advisories and official records. Exploit/PoC links are deliberately left out.